diff --git a/doc/api/ffi.md b/doc/api/ffi.md
index 37ccf2a719bc1a..01abdc0b6bbdb1 100644
--- a/doc/api/ffi.md
+++ b/doc/api/ffi.md
@@ -124,18 +124,18 @@ such as `0` and `1`; JavaScript `true` and `false` are not accepted.
 
 Functions and callbacks are described with signature objects.
 
-Supported fields:
+Signature objects may contain the following properties, both of which are
+optional:
 
-* `result`, `return`, or `returns` for the return type.
-* `parameters` or `arguments` for the parameter type list.
+* `return` {string} A [type name][type names] specifying the return type of the
+  function or callback. **Default:** `'void'`.
+* `arguments` {string\[]} An array of [type names][] specifying the argument
+  type list of the function or callback. **Default:** `[]`.
 
-Only one return-type field and one parameter-list field may be present in a
-single signature object.
-
-```cjs
+```js
 const signature = {
-  result: 'i32',
-  parameters: ['i32', 'i32'],
+  return: 'i32',
+  arguments: ['i32', 'i32'],
 };
 ```
 
@@ -193,7 +193,7 @@ import { dlopen } from 'node:ffi';
 
 {
   using handle = dlopen('./mylib.so', {
-    add_i32: { parameters: ['i32', 'i32'], result: 'i32' },
+    add_i32: { arguments: ['i32', 'i32'], return: 'i32' },
   });
   console.log(handle.functions.add_i32(20, 22));
 } // handle.lib.close() is invoked automatically here.
@@ -203,8 +203,8 @@ import { dlopen } from 'node:ffi';
 import { dlopen } from 'node:ffi';
 
 const { lib, functions } = dlopen('./mylib.so', {
-  add_i32: { parameters: ['i32', 'i32'], result: 'i32' },
-  string_length: { parameters: ['pointer'], result: 'u64' },
+  add_i32: { arguments: ['i32', 'i32'], return: 'i32' },
+  string_length: { arguments: ['pointer'], return: 'u64' },
 });
 
 console.log(functions.add_i32(20, 22));
@@ -214,8 +214,8 @@ console.log(functions.add_i32(20, 22));
 const { dlopen } = require('node:ffi');
 
 const { lib, functions } = dlopen('./mylib.so', {
-  add_i32: { parameters: ['i32', 'i32'], result: 'i32' },
-  string_length: { parameters: ['pointer'], result: 'u64' },
+  add_i32: { arguments: ['i32', 'i32'], return: 'i32' },
+  string_length: { arguments: ['pointer'], return: 'u64' },
 });
 
 console.log(functions.add_i32(20, 22));
@@ -356,8 +356,8 @@ const { DynamicLibrary } = require('node:ffi');
 
 const lib = new DynamicLibrary('./mylib.so');
 const add = lib.getFunction('add_i32', {
-  parameters: ['i32', 'i32'],
-  result: 'i32',
+  arguments: ['i32', 'i32'],
+  return: 'i32',
 });
 
 console.log(add(20, 22));
@@ -407,7 +407,7 @@ const { DynamicLibrary } = require('node:ffi');
 const lib = new DynamicLibrary('./mylib.so');
 
 const callback = lib.registerCallback(
-  { parameters: ['i32'], result: 'i32' },
+  { arguments: ['i32'], return: 'i32' },
   (value) => value * 2,
 );
 ```
@@ -417,7 +417,7 @@ Callbacks are subject to the following restrictions:
 * They must be invoked on the same system thread where they were created.
 * They must not throw exceptions.
 * They must not return promises.
-* They must return a value compatible with the declared result type.
+* They must return a value compatible with the declared return type.
 * They must not call `library.close()` on their owning library while running.
 * They must not unregister themselves while running.
 
@@ -465,7 +465,7 @@ JavaScript `number` values that match the declared type.
 
 For 64-bit integer types (`i64` and `u64`), pass JavaScript `bigint` values.
 
-For pointer-like parameters:
+For pointer-like arguments:
 
 * `null` and `undefined` are passed as null pointers.
 * `string` values are copied to temporary NUL-terminated UTF-8 strings for the
@@ -727,3 +727,4 @@ and keep callback and pointer lifetimes explicit on the native side.
 [`--allow-ffi`]: cli.md#--allow-ffi
 [`ffi.toBuffer(pointer, length, copy)`]: #ffitobufferpointer-length-copy
 [`using`]: https://tc39.es/proposal-explicit-resource-management/#sec-using-declarations
+[type names]: #type-names
diff --git a/lib/internal/ffi-shared-buffer.js b/lib/internal/ffi-shared-buffer.js
index bce51fd79959dd..c5a769c394f11a 100644
--- a/lib/internal/ffi-shared-buffer.js
+++ b/lib/internal/ffi-shared-buffer.js
@@ -31,18 +31,14 @@ const {
   TypeError,
 } = primordials;
 
-const {
-  codes: {
-    ERR_INTERNAL_ASSERTION,
-  },
-} = require('internal/errors');
+const assert = require('internal/assert');
 
 const {
   DynamicLibrary,
   charIsSigned,
+  kSbArguments,
   kSbInvokeSlow,
-  kSbParams,
-  kSbResult,
+  kSbReturn,
   kSbSharedBuffer,
   uintptrMax,
 } = internalBinding('ffi');
@@ -159,11 +155,9 @@ function writeNumericArg(view, info, offset, arg, index) {
     return;
   }
 
-  /* c8 ignore start */
   // Unreachable: caller filters out non-numeric kinds.
-  throw new ERR_INTERNAL_ASSERTION(
-    `FFI: writeNumericArg reached with unexpected kind="${kind}"`);
-  /* c8 ignore stop */
+  /* c8 ignore next */
+  assert.fail(`FFI: writeNumericArg reached with unexpected kind="${kind}"`);
 }
 
 // Returns true on fast-path success, false when the caller must fall back
@@ -208,51 +202,46 @@ function inheritMetadata(wrapper, rawFn, nargs) {
 // arguments out of it into invocation-local storage before `ffi_call` and
 // reads the return value back only after, so nested/reentrant calls into
 // the same function are safe.
-function wrapWithSharedBuffer(rawFn, parameters, resultType) {
-  if (rawFn === undefined || rawFn === null) return rawFn;
+function wrapWithSharedBuffer(rawFn, signature) {
+  if (rawFn == null) return rawFn;
   const buffer = rawFn[kSbSharedBuffer];
   if (buffer === undefined) return rawFn;
 
   // Callers without explicit signature info (the `functions` accessor
-  // patch below) rely on the `kSbParams` / `kSbResult` metadata attached
+  // patch below) rely on the `kSbArguments` / `kSbReturn` metadata attached
   // by the native `CreateFunction`.
-  if (parameters === undefined) parameters = rawFn[kSbParams];
-  if (resultType === undefined) resultType = rawFn[kSbResult];
-  // `CreateFunction` always attaches these for SB-eligible functions.
-  // Missing here means the native side and this wrapper are out of sync.
-  /* c8 ignore start */
-  if (parameters === undefined || resultType === undefined) {
-    throw new ERR_INTERNAL_ASSERTION(
-      'FFI: shared-buffer raw function is missing kSbParams or kSbResult');
+  let argumentTypes, returnType;
+  if (signature === undefined) {
+    argumentTypes = rawFn[kSbArguments];
+    returnType = rawFn[kSbReturn];
+
+    // `CreateFunction` always attaches these for SB-eligible functions.
+    // Missing here means the native side and this wrapper are out of sync.
+    assert(argumentTypes !== undefined && returnType !== undefined,
+           'FFI: shared-buffer raw function is missing kSbArguments or kSbReturn');
+  } else {
+    argumentTypes = signature.arguments ?? [];
+    returnType = signature.return ?? 'void';
   }
-  /* c8 ignore stop */
 
   const slowInvoke = rawFn[kSbInvokeSlow];
   const view = new DataView(buffer);
   let retGetter = null;
-  if (resultType !== 'void') {
-    const retInfo = sbTypeInfo[resultType];
-    /* c8 ignore start */
-    if (retInfo === undefined) {
-      throw new ERR_INTERNAL_ASSERTION(
-        `FFI: shared-buffer type table missing entry for result type "${resultType}"`);
-    }
-    /* c8 ignore stop */
+  if (returnType !== 'void') {
+    const retInfo = sbTypeInfo[returnType];
+    assert(retInfo !== undefined,
+           `FFI: shared-buffer type table missing entry for return type "${returnType}"`);
     retGetter = retInfo.get;
   }
 
-  const nargs = parameters.length;
+  const nargs = argumentTypes.length;
   const argInfos = [];
   const argOffsets = [];
   let anyPointer = false;
   for (let i = 0; i < nargs; i++) {
-    const info = sbTypeInfo[parameters[i]];
-    /* c8 ignore start */
-    if (info === undefined) {
-      throw new ERR_INTERNAL_ASSERTION(
-        `FFI: shared-buffer type table missing entry for parameter type "${parameters[i]}"`);
-    }
-    /* c8 ignore stop */
+    const info = sbTypeInfo[argumentTypes[i]];
+    assert(info !== undefined,
+           `FFI: shared-buffer type table missing entry for argument type "${argumentTypes[i]}"`);
     // Push the `sbTypeInfo` entry directly (entries with the same `kind`
     // share a shape, keeping `writeNumericArg`'s call sites
     // low-polymorphism) and store offsets in a parallel array to avoid
@@ -267,13 +256,8 @@ function wrapWithSharedBuffer(rawFn, parameters, resultType) {
     // Pointer signatures need a per-arg runtime type check and fall back
     // to the native slow-path invoker for non-BigInt pointer arguments,
     // so arity specialization wouldn't buy much here.
-    /* c8 ignore start */
-    if (slowInvoke === undefined) {
-      throw new ERR_INTERNAL_ASSERTION(
-        'FFI: shared-buffer raw function with pointer arguments is ' +
-        'missing kSbInvokeSlow');
-    }
-    /* c8 ignore stop */
+    assert(slowInvoke !== undefined,
+           'FFI: shared-buffer raw function with pointer arguments is missing kSbInvokeSlow');
     wrapper = function(...args) {
       if (args.length !== nargs) {
         throwFFIArgCountError(nargs, args.length);
@@ -542,19 +526,6 @@ function buildNumericWrapper(
   };
 }
 
-// Accept-set mirrors the native `ParseFunctionSignature` in
-// `src/ffi/types.cc`. `ParseFunctionSignature` additionally throws when
-// multiple aliases are set at once. The wrapper runs before the native
-// call, so those conflicts still surface from the native side regardless
-// of which alias we happen to read here.
-function sigParams(sig) {
-  return sig.parameters ?? sig.arguments ?? [];
-}
-
-function sigResult(sig) {
-  return sig.result ?? sig.return ?? sig.returns ?? 'void';
-}
-
 // The native invoker for SB-eligible symbols is `InvokeFunctionSB`, which
 // reads arguments from the shared buffer populated by
 // `wrapWithSharedBuffer`. These patches make sure every path that surfaces
@@ -563,11 +534,11 @@ function sigResult(sig) {
 const rawGetFunction = DynamicLibrary.prototype.getFunction;
 const rawGetFunctions = DynamicLibrary.prototype.getFunctions;
 
-DynamicLibrary.prototype.getFunction = function getFunction(name, sig) {
-  // Native `DynamicLibrary::GetFunction` validates `sig`, so by the time
-  // we have `raw` we know `sig` is a valid object.
-  const raw = FunctionPrototypeCall(rawGetFunction, this, name, sig);
-  return wrapWithSharedBuffer(raw, sigParams(sig), sigResult(sig));
+DynamicLibrary.prototype.getFunction = function getFunction(name, signature) {
+  // Native `DynamicLibrary::GetFunction` validates `signature`, so by the time
+  // we have `raw` we know `signature` is a valid object.
+  const raw = FunctionPrototypeCall(rawGetFunction, this, name, signature);
+  return wrapWithSharedBuffer(raw, signature);
 };
 
 DynamicLibrary.prototype.getFunctions = function getFunctions(definitions) {
@@ -583,13 +554,12 @@ DynamicLibrary.prototype.getFunctions = function getFunctions(definitions) {
   for (let i = 0; i < keys.length; i++) {
     const name = keys[i];
     // No `definitions`: native side returned every cached function, so we
-    // wrap using each function's own `kSbParams` / `kSbResult` metadata
+    // wrap using each function's own `kSbArguments` / `kSbReturn` metadata
     // (same fallback as the `functions` accessor).
     if (definitions === undefined) {
       out[name] = wrapWithSharedBuffer(raw[name]);
     } else {
-      const sig = definitions[name];
-      out[name] = wrapWithSharedBuffer(raw[name], sigParams(sig), sigResult(sig));
+      out[name] = wrapWithSharedBuffer(raw[name], definitions[name]);
     }
   }
   return out;
@@ -602,16 +572,12 @@ DynamicLibrary.prototype.getFunctions = function getFunctions(definitions) {
   // uninitialized buffer.
   const functionsDescriptor =
     ObjectGetOwnPropertyDescriptor(DynamicLibrary.prototype, 'functions');
-  /* c8 ignore start */
-  if (functionsDescriptor === undefined || !functionsDescriptor.get) {
-    // Missing getter means the native and JS sides are out of sync; silently
-    // skipping the patch would expose the fast-path-against-uninitialized-buffer
-    // footgun this whole block exists to prevent.
-    throw new ERR_INTERNAL_ASSERTION(
-      'FFI: DynamicLibrary.prototype.functions accessor not found or has no getter');
-  }
-  /* c8 ignore stop */
-  const origGetter = functionsDescriptor.get;
+  const origGetter = functionsDescriptor?.get;
+  // Missing getter means the native and JS sides are out of sync; silently
+  // skipping the patch would expose the fast-path-against-uninitialized-buffer
+  // footgun this whole block exists to prevent.
+  assert(origGetter !== undefined,
+         'FFI: DynamicLibrary.prototype.functions accessor not found or has no getter');
   ObjectDefineProperty(DynamicLibrary.prototype, 'functions', {
     __proto__: null,
     configurable: true,
diff --git a/src/env_properties.h b/src/env_properties.h
index 113cc066ab2c5d..896b664b64eea2 100644
--- a/src/env_properties.h
+++ b/src/env_properties.h
@@ -48,8 +48,8 @@
   V(async_id_symbol, "async_id_symbol")                                        \
   V(ffi_sb_shared_buffer_symbol, "ffi_sb_shared_buffer_symbol")                \
   V(ffi_sb_invoke_slow_symbol, "ffi_sb_invoke_slow_symbol")                    \
-  V(ffi_sb_params_symbol, "ffi_sb_params_symbol")                              \
-  V(ffi_sb_result_symbol, "ffi_sb_result_symbol")                              \
+  V(ffi_sb_arguments_symbol, "ffi_sb_arguments_symbol")                        \
+  V(ffi_sb_return_symbol, "ffi_sb_return_symbol")                              \
   V(constructor_key_symbol, "constructor_key_symbol")                          \
   V(handle_onclose_symbol, "handle_onclose")                                   \
   V(no_message_symbol, "no_message_symbol")                                    \
@@ -293,7 +293,6 @@
   V(password_string, "password")                                               \
   V(path_string, "path")                                                       \
   V(pathname_string, "pathname")                                               \
-  V(parameters_string, "parameters")                                           \
   V(pending_handle_string, "pendingHandle")                                    \
   V(permission_string, "permission")                                           \
   V(phase_string, "phase")                                                     \
@@ -329,9 +328,8 @@
   V(require_string, "require")                                                 \
   V(resource_string, "resource")                                               \
   V(result_string, "result")                                                   \
-  V(return_string, "return")                                                   \
-  V(returns_string, "returns")                                                 \
   V(return_arrays_string, "returnArrays")                                      \
+  V(return_string, "return")                                                   \
   V(salt_length_string, "saltLength")                                          \
   V(search_string, "search")                                                   \
   V(servername_string, "servername")                                           \
diff --git a/src/ffi/types.cc b/src/ffi/types.cc
index e8469ebc0bbcc6..7f31845a06736c 100644
--- a/src/ffi/types.cc
+++ b/src/ffi/types.cc
@@ -83,63 +83,26 @@ Maybe<FunctionSignature> ParseFunctionSignature(Environment* env,
                                                 std::string_view name,
                                                 Local<Object> signature) {
   Local<Context> context = env->context();
-  Local<String> returns_key = env->returns_string();
   Local<String> return_key = env->return_string();
-  Local<String> result_key = env->result_string();
-  Local<String> parameters_key = env->parameters_string();
   Local<String> arguments_key = env->arguments_string();
 
-  bool has_returns;
   bool has_return;
-  bool has_result;
-  bool has_parameters;
   bool has_arguments;
 
-  if (!signature->Has(context, returns_key).To(&has_returns) ||
-      !signature->Has(context, return_key).To(&has_return) ||
-      !signature->Has(context, result_key).To(&has_result) ||
-      !signature->Has(context, parameters_key).To(&has_parameters) ||
+  if (!signature->Has(context, return_key).To(&has_return) ||
       !signature->Has(context, arguments_key).To(&has_arguments)) {
     return {};
   }
 
-  if (has_returns + has_return + has_result > 1) {
-    THROW_ERR_INVALID_ARG_VALUE(
-        env,
-        "Function signature of %s"
-        " must have either 'returns', 'return' or 'result' "
-        "property",
-        name);
-    return {};
-  }
-
-  if (has_arguments && has_parameters) {
-    THROW_ERR_INVALID_ARG_VALUE(env,
-                                "Function signature of %s"
-                                " must have either 'parameters' or 'arguments' "
-                                "property",
-                                name);
-    return {};
-  }
-
   ffi_type* return_type = &ffi_type_void;
   std::vector<ffi_type*> args;
   std::string return_type_name = "void";
   std::vector<std::string> arg_type_names;
 
   Isolate* isolate = env->isolate();
-  if (has_returns || has_return || has_result) {
-    Local<String> return_type_key;
-    if (has_returns) {
-      return_type_key = returns_key;
-    } else if (has_return) {
-      return_type_key = return_key;
-    } else {
-      return_type_key = result_key;
-    }
-
+  if (has_return) {
     Local<Value> return_type_val;
-    if (!signature->Get(context, return_type_key).ToLocal(&return_type_val)) {
+    if (!signature->Get(context, return_key).ToLocal(&return_type_val)) {
       return {};
     }
 
@@ -162,10 +125,9 @@ Maybe<FunctionSignature> ParseFunctionSignature(Environment* env,
     return_type_name = return_type_str.ToString();
   }
 
-  if (has_arguments || has_parameters) {
+  if (has_arguments) {
     Local<Value> arguments_val;
-    if (!signature->Get(context, has_arguments ? arguments_key : parameters_key)
-             .ToLocal(&arguments_val)) {
+    if (!signature->Get(context, arguments_key).ToLocal(&arguments_val)) {
       return {};
     }
 
diff --git a/src/node_ffi.cc b/src/node_ffi.cc
index 34f999b015123b..e0071baecb7e95 100644
--- a/src/node_ffi.cc
+++ b/src/node_ffi.cc
@@ -312,28 +312,28 @@ MaybeLocal<Function> DynamicLibrary::CreateFunction(
 
     // Attach the original signature type names so the JS wrapper can
     // rebuild the signature from a raw function when the caller did not
-    // pass parameters and result explicitly. The `lib.functions` accessor
+    // pass arguments and return explicitly. The `lib.functions` accessor
     // path relies on this.
-    Local<Value> params_arr;
-    if (!ToV8Value(context, fn->arg_type_names, isolate).ToLocal(&params_arr)) {
+    Local<Value> args_arr;
+    if (!ToV8Value(context, fn->arg_type_names, isolate).ToLocal(&args_arr)) {
       return MaybeLocal<Function>();
     }
     if (!ret->DefineOwnProperty(context,
-                                env->ffi_sb_params_symbol(),
-                                params_arr,
+                                env->ffi_sb_arguments_symbol(),
+                                args_arr,
                                 internal_attrs)
              .FromMaybe(false)) {
       return MaybeLocal<Function>();
     }
 
-    Local<Value> result_name;
+    Local<Value> return_name;
     if (!ToV8Value(context, fn->return_type_name, isolate)
-             .ToLocal(&result_name)) {
+             .ToLocal(&return_name)) {
       return MaybeLocal<Function>();
     }
     if (!ret->DefineOwnProperty(context,
-                                env->ffi_sb_result_symbol(),
-                                result_name,
+                                env->ffi_sb_return_symbol(),
+                                return_name,
                                 internal_attrs)
              .FromMaybe(false)) {
       return MaybeLocal<Function>();
@@ -1196,13 +1196,13 @@ static void Initialize(Local<Object> target,
       .Check();
   target
       ->Set(context,
-            FIXED_ONE_BYTE_STRING(isolate, "kSbParams"),
-            env->ffi_sb_params_symbol())
+            FIXED_ONE_BYTE_STRING(isolate, "kSbArguments"),
+            env->ffi_sb_arguments_symbol())
       .Check();
   target
       ->Set(context,
-            FIXED_ONE_BYTE_STRING(isolate, "kSbResult"),
-            env->ffi_sb_result_symbol())
+            FIXED_ONE_BYTE_STRING(isolate, "kSbReturn"),
+            env->ffi_sb_return_symbol())
       .Check();
 }
 
diff --git a/test/ffi/ffi-test-common.js b/test/ffi/ffi-test-common.js
index 7cc64eb00cda2e..86e56de8ec2163 100644
--- a/test/ffi/ffi-test-common.js
+++ b/test/ffi/ffi-test-common.js
@@ -31,56 +31,56 @@ function ensureFixtureLibrary() {
 ensureFixtureLibrary();
 
 const fixtureSymbols = {
-  add_i8: { parameters: ['i8', 'i8'], result: 'i8' },
-  add_u8: { parameters: ['u8', 'u8'], result: 'u8' },
-  add_i16: { parameters: ['i16', 'i16'], result: 'i16' },
-  add_u16: { parameters: ['u16', 'u16'], result: 'u16' },
-  add_i32: { parameters: ['i32', 'i32'], result: 'i32' },
-  add_u32: { parameters: ['u32', 'u32'], result: 'u32' },
-  add_i64: { parameters: ['i64', 'i64'], result: 'i64' },
-  add_u64: { parameters: ['u64', 'u64'], result: 'u64' },
-  identity_char: { parameters: ['char'], result: 'char' },
-  char_is_signed: { parameters: [], result: 'i32' },
-  add_f32: { parameters: ['f32', 'f32'], result: 'f32' },
-  multiply_f64: { parameters: ['f64', 'f64'], result: 'f64' },
-  identity_pointer: { parameters: ['pointer'], result: 'pointer' },
-  pointer_to_usize: { parameters: ['pointer'], result: 'u64' },
-  usize_to_pointer: { parameters: ['u64'], result: 'pointer' },
-  string_length: { parameters: ['pointer'], result: 'u64' },
-  string_concat: { parameters: ['pointer', 'pointer'], result: 'pointer' },
-  string_duplicate: { parameters: ['pointer'], result: 'pointer' },
-  free_string: { parameters: ['pointer'], result: 'void' },
-  fill_buffer: { parameters: ['pointer', 'u64', 'u32'], result: 'void' },
-  sum_buffer: { parameters: ['pointer', 'u64'], result: 'u64' },
-  reverse_buffer: { parameters: ['pointer', 'u64'], result: 'void' },
-  logical_and: { parameters: ['i32', 'i32'], result: 'i32' },
-  logical_or: { parameters: ['i32', 'i32'], result: 'i32' },
-  logical_not: { parameters: ['i32'], result: 'i32' },
-  increment_counter: { parameters: [], result: 'void' },
-  get_counter: { parameters: [], result: 'i32' },
-  reset_counter: { parameters: [], result: 'void' },
-  call_int_callback: { parameters: ['pointer', 'i32'], result: 'i32' },
-  call_int8_callback: { parameters: ['pointer', 'i8'], result: 'i8' },
-  call_pointer_callback_is_null: { parameters: ['pointer'], result: 'i32' },
-  call_void_callback: { parameters: ['pointer'], result: 'void' },
-  call_string_callback: { parameters: ['function', 'pointer'], result: 'void' },
-  call_binary_int_callback: { parameters: ['function', 'i32', 'i32'], result: 'i32' },
-  call_callback_multiple_times: { parameters: ['pointer', 'i32'], result: 'void' },
-  divide_i32: { parameters: ['i32', 'i32'], result: 'i32' },
-  safe_strlen: { parameters: ['pointer'], result: 'i32' },
-  sum_five_i32: { parameters: ['i32', 'i32', 'i32', 'i32', 'i32'], result: 'i32' },
-  sum_five_f64: { parameters: ['f64', 'f64', 'f64', 'f64', 'f64'], result: 'f64' },
-  mixed_operation: { parameters: ['i32', 'f32', 'f64', 'u32'], result: 'f64' },
-  allocate_memory: { parameters: ['u64'], result: 'pointer' },
-  deallocate_memory: { parameters: ['pointer'], result: 'void' },
-  array_get_i32: { parameters: ['pointer', 'u64'], result: 'i32' },
-  array_set_i32: { parameters: ['pointer', 'u64', 'i32'], result: 'void' },
-  array_get_f64: { parameters: ['pointer', 'u64'], result: 'f64' },
-  array_set_f64: { parameters: ['pointer', 'u64', 'f64'], result: 'void' },
+  add_i8: { arguments: ['i8', 'i8'], return: 'i8' },
+  add_u8: { arguments: ['u8', 'u8'], return: 'u8' },
+  add_i16: { arguments: ['i16', 'i16'], return: 'i16' },
+  add_u16: { arguments: ['u16', 'u16'], return: 'u16' },
+  add_i32: { arguments: ['i32', 'i32'], return: 'i32' },
+  add_u32: { arguments: ['u32', 'u32'], return: 'u32' },
+  add_i64: { arguments: ['i64', 'i64'], return: 'i64' },
+  add_u64: { arguments: ['u64', 'u64'], return: 'u64' },
+  identity_char: { arguments: ['char'], return: 'char' },
+  char_is_signed: { arguments: [], return: 'i32' },
+  add_f32: { arguments: ['f32', 'f32'], return: 'f32' },
+  multiply_f64: { arguments: ['f64', 'f64'], return: 'f64' },
+  identity_pointer: { arguments: ['pointer'], return: 'pointer' },
+  pointer_to_usize: { arguments: ['pointer'], return: 'u64' },
+  usize_to_pointer: { arguments: ['u64'], return: 'pointer' },
+  string_length: { arguments: ['pointer'], return: 'u64' },
+  string_concat: { arguments: ['pointer', 'pointer'], return: 'pointer' },
+  string_duplicate: { arguments: ['pointer'], return: 'pointer' },
+  free_string: { arguments: ['pointer'], return: 'void' },
+  fill_buffer: { arguments: ['pointer', 'u64', 'u32'], return: 'void' },
+  sum_buffer: { arguments: ['pointer', 'u64'], return: 'u64' },
+  reverse_buffer: { arguments: ['pointer', 'u64'], return: 'void' },
+  logical_and: { arguments: ['i32', 'i32'], return: 'i32' },
+  logical_or: { arguments: ['i32', 'i32'], return: 'i32' },
+  logical_not: { arguments: ['i32'], return: 'i32' },
+  increment_counter: { arguments: [], return: 'void' },
+  get_counter: { arguments: [], return: 'i32' },
+  reset_counter: { arguments: [], return: 'void' },
+  call_int_callback: { arguments: ['pointer', 'i32'], return: 'i32' },
+  call_int8_callback: { arguments: ['pointer', 'i8'], return: 'i8' },
+  call_pointer_callback_is_null: { arguments: ['pointer'], return: 'i32' },
+  call_void_callback: { arguments: ['pointer'], return: 'void' },
+  call_string_callback: { arguments: ['function', 'pointer'], return: 'void' },
+  call_binary_int_callback: { arguments: ['function', 'i32', 'i32'], return: 'i32' },
+  call_callback_multiple_times: { arguments: ['pointer', 'i32'], return: 'void' },
+  divide_i32: { arguments: ['i32', 'i32'], return: 'i32' },
+  safe_strlen: { arguments: ['pointer'], return: 'i32' },
+  sum_five_i32: { arguments: ['i32', 'i32', 'i32', 'i32', 'i32'], return: 'i32' },
+  sum_five_f64: { arguments: ['f64', 'f64', 'f64', 'f64', 'f64'], return: 'f64' },
+  mixed_operation: { arguments: ['i32', 'f32', 'f64', 'u32'], return: 'f64' },
+  allocate_memory: { arguments: ['u64'], return: 'pointer' },
+  deallocate_memory: { arguments: ['pointer'], return: 'void' },
+  array_get_i32: { arguments: ['pointer', 'u64'], return: 'i32' },
+  array_set_i32: { arguments: ['pointer', 'u64', 'i32'], return: 'void' },
+  array_get_f64: { arguments: ['pointer', 'u64'], return: 'f64' },
+  array_set_f64: { arguments: ['pointer', 'u64', 'f64'], return: 'void' },
 };
 
 if (!common.isWindows) {
-  fixtureSymbols.readonly_memory = { parameters: [], result: 'pointer' };
+  fixtureSymbols.readonly_memory = { arguments: [], return: 'pointer' };
 }
 
 function cString(value) {
diff --git a/test/ffi/test-ffi-calls.js b/test/ffi/test-ffi-calls.js
index ef43fb0a6f7274..14020c5a6c78ae 100644
--- a/test/ffi/test-ffi-calls.js
+++ b/test/ffi/test-ffi-calls.js
@@ -59,8 +59,8 @@ test('ffi bool signatures use uint8 values', () => {
     assert.strictEqual(symbols.logical_not(0), 1);
 
     const boolAdder = lib.getFunction('add_u8', {
-      parameters: ['bool', 'bool'],
-      result: 'bool',
+      arguments: ['bool', 'bool'],
+      return: 'bool',
     });
     assert.strictEqual(boolAdder(1, 0), 1);
     assert.throws(() => boolAdder(true, false), /Argument 0 must be a uint8/);
@@ -148,15 +148,15 @@ test('ffi callbacks can be registered and invoked', () => {
   const { lib, functions: symbols } = getLibrary();
   const seen = [];
   const intCallback = lib.registerCallback(
-    { parameters: ['i32'], result: 'i32' },
+    { arguments: ['i32'], return: 'i32' },
     (value) => value * 2,
   );
   const stringCallback = lib.registerCallback(
-    { parameters: ['pointer'], result: 'void' },
+    { arguments: ['pointer'], return: 'void' },
     (ptr) => seen.push(ffi.toString(ptr)),
   );
   const binaryCallback = lib.registerCallback(
-    { arguments: ['i32', 'i32'], returns: 'i32' },
+    { arguments: ['i32', 'i32'], return: 'i32' },
     (a, b) => a + b,
   );
 
@@ -166,8 +166,8 @@ test('ffi callbacks can be registered and invoked', () => {
     assert.deepStrictEqual(seen, ['hello callback']);
     assert.strictEqual(symbols.call_binary_int_callback(binaryCallback, 19, 23), 42);
 
-    const nullPointerCallback = lib.registerCallback({ result: 'pointer' }, () => null);
-    const undefinedPointerCallback = lib.registerCallback({ result: 'pointer' }, () => undefined);
+    const nullPointerCallback = lib.registerCallback({ return: 'pointer' }, () => null);
+    const undefinedPointerCallback = lib.registerCallback({ return: 'pointer' }, () => undefined);
     try {
       assert.strictEqual(symbols.call_pointer_callback_is_null(nullPointerCallback), 1);
       assert.strictEqual(symbols.call_pointer_callback_is_null(undefinedPointerCallback), 1);
@@ -191,7 +191,7 @@ test('ffi callback ref and unref APIs work', () => {
     called = true;
   });
   const countingCallback = lib.registerCallback(
-    { parameters: ['i32'], result: 'i32' },
+    { arguments: ['i32'], return: 'i32' },
     (value) => {
       values.push(value);
       return 0;
@@ -271,7 +271,7 @@ const ffi = require('node:ffi');
 const { fixtureSymbols, libraryPath } = require(${JSON.stringify(require.resolve('./ffi-test-common'))});
 const { lib, functions } = ffi.dlopen(libraryPath, fixtureSymbols);
 const callback = lib.registerCallback(
-  { parameters: ['i32'], result: 'i32' },
+  { arguments: ['i32'], return: 'i32' },
   () => (${returnExpression}),
 );
 functions.call_int_callback(callback, 21);`,
@@ -294,7 +294,7 @@ const ffi = require('node:ffi');
 const { fixtureSymbols, libraryPath } = require(${JSON.stringify(require.resolve('./ffi-test-common'))});
 const { lib, functions } = ffi.dlopen(libraryPath, fixtureSymbols);
 const callback = lib.registerCallback(
-  { parameters: ['i32'], result: 'i32' },
+  { arguments: ['i32'], return: 'i32' },
   () => { ${callbackBody} },
 );
 functions.call_int_callback(callback, 21);`,
@@ -325,7 +325,7 @@ const ffi = require('node:ffi');
 const { fixtureSymbols, libraryPath } = require(${JSON.stringify(require.resolve('./ffi-test-common'))});
 const { lib } = ffi.dlopen(libraryPath, fixtureSymbols);
 const callback = lib.registerCallback(
-  { parameters: ['i32'], result: 'i32' },
+  { arguments: ['i32'], return: 'i32' },
   (value) => value * 2,
 );
 new Worker(${JSON.stringify(workerSource)}, { eval: true, workerData: callback });`,
@@ -359,7 +359,7 @@ test('ffi unrefCallback releases callback function', async () => {
     let callback = () => 1;
     const ref = new WeakRef(callback);
     const pointer = lib.registerCallback(
-      { parameters: ['i32'], result: 'i32' },
+      { arguments: ['i32'], return: 'i32' },
       callback,
     );
 
@@ -383,7 +383,7 @@ test('ffi unrefCallback zero-fills narrow callback return', async () => {
     let callback = () => 1;
     const ref = new WeakRef(callback);
     const pointer = lib.registerCallback(
-      { parameters: ['i8'], result: 'i8' },
+      { arguments: ['i8'], return: 'i8' },
       callback,
     );
 
@@ -406,7 +406,7 @@ test('ffi refCallback retains callback function', async () => {
   try {
     let callback = () => 1;
     const ref = new WeakRef(callback);
-    const pointer = lib.registerCallback({ result: 'i32' }, callback);
+    const pointer = lib.registerCallback({ return: 'i32' }, callback);
 
     lib.unrefCallback(pointer);
     lib.refCallback(pointer);
diff --git a/test/ffi/test-ffi-dynamic-library.js b/test/ffi/test-ffi-dynamic-library.js
index e3171b57124250..ba0f8a383ffd8b 100644
--- a/test/ffi/test-ffi-dynamic-library.js
+++ b/test/ffi/test-ffi-dynamic-library.js
@@ -27,7 +27,7 @@ test('dlopen resolves symbols from the current process with null path', {
   skip: common.isWindows,
 }, () => {
   const { lib, functions } = ffi.dlopen(null, {
-    uv_os_getpid: { result: 'i32', parameters: [] },
+    uv_os_getpid: { return: 'i32', arguments: [] },
   });
 
   try {
@@ -41,8 +41,8 @@ test('dlopen resolves symbols from the current process with null path', {
 test('dlopen resolves functions from definitions', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
     add_i32: fixtureSymbols.add_i32,
-    add_f32: { returns: 'f32', arguments: ['f32', 'f32'] },
-    add_u64: { return: 'u64', parameters: ['u64', 'u64'] },
+    add_f32: { return: 'f32', arguments: ['f32', 'f32'] },
+    add_u64: { return: 'u64', arguments: ['u64', 'u64'] },
   });
 
   try {
@@ -73,7 +73,7 @@ test('DynamicLibrary exposes functions and symbols', () => {
   try {
     const addI32 = lib.getFunction('add_i32', fixtureSymbols.add_i32);
     const addU64 = lib.getFunction('add_u64', {
-      returns: 'u64',
+      return: 'u64',
       arguments: ['u64', 'u64'],
     });
     const addI32Ptr = lib.getSymbol('add_i32');
@@ -84,7 +84,7 @@ test('DynamicLibrary exposes functions and symbols', () => {
     assert.strictEqual(addI32.pointer, addI32Ptr);
 
     const functions = lib.getFunctions({
-      add_f32: { result: 'f32', parameters: ['f32', 'f32'] },
+      add_f32: { return: 'f32', arguments: ['f32', 'f32'] },
       add_i64: { return: 'i64', arguments: ['i64', 'i64'] },
     });
 
@@ -115,7 +115,7 @@ test('getFunction caches signatures consistently', () => {
     );
 
     assert.throws(() => {
-      lib.getFunction('add_i32', { parameters: ['u32', 'u32'], result: 'u32' });
+      lib.getFunction('add_i32', { arguments: ['u32', 'u32'], return: 'u32' });
     }, /already requested with a different signature/);
   } finally {
     lib.close();
@@ -226,7 +226,7 @@ test('dynamic library APIs validate failures and bad signatures', () => {
   assert.throws(() => {
     ffi.dlopen(libraryPath, {
       add_i32: fixtureSymbols.add_i32,
-      missing_symbol: { result: 'void', parameters: [] },
+      missing_symbol: { return: 'void', arguments: [] },
     });
   }, /dlsym failed:/);
 
@@ -245,7 +245,7 @@ test('dynamic library APIs validate failures and bad signatures', () => {
 
   try {
     assert.throws(() => {
-      lib.getFunction('missing_symbol', { result: 'void', parameters: [] });
+      lib.getFunction('missing_symbol', { return: 'void', arguments: [] });
     }, /dlsym failed:/);
 
     assert.throws(() => {
@@ -259,21 +259,21 @@ test('dynamic library APIs validate failures and bad signatures', () => {
     assert.throws(() => {
       lib.getFunctions({
         add_i32: fixtureSymbols.add_i32,
-        missing_symbol: { result: 'void', parameters: [] },
+        missing_symbol: { return: 'void', arguments: [] },
       });
     }, /dlsym failed:/);
 
     assert.strictEqual(lib.getFunction('add_i32', {
-      result: 'pointer',
-      parameters: ['pointer'],
+      return: 'pointer',
+      arguments: ['pointer'],
     }).pointer, lib.getSymbol('add_i32'));
 
     assert.throws(() => {
-      lib.getFunction('add_i32', { result: 'i32\0bad', parameters: [] });
+      lib.getFunction('add_i32', { return: 'i32\0bad', arguments: [] });
     }, /Return value type of function add_i32 must not contain null bytes/);
 
     assert.throws(() => {
-      lib.getFunction('add_i32', { result: 'i32', parameters: ['i32\0bad'] });
+      lib.getFunction('add_i32', { return: 'i32', arguments: ['i32\0bad'] });
     }, /Argument 0 of function add_i32 must not contain null bytes/);
 
     assert.throws(() => {
@@ -305,30 +305,14 @@ test('dynamic library APIs validate failures and bad signatures', () => {
     });
 
     assert.throws(() => {
-      lib.getFunction('add_i32', {
-        result: 'i32',
-        return: 'i32',
-        parameters: ['i32', 'i32'],
-      });
-    }, /must have either 'returns', 'return' or 'result' property/);
-
-    assert.throws(() => {
-      lib.getFunction('add_i32', {
-        result: 'i32',
-        parameters: ['i32', 'i32'],
-        arguments: ['i32', 'i32'],
-      });
-    }, /must have either 'parameters' or 'arguments' property/);
-
-    assert.throws(() => {
-      lib.getFunction('add_i32', { result: 'bogus', parameters: [] });
+      lib.getFunction('add_i32', { return: 'bogus', arguments: [] });
     }, /Unsupported FFI type: bogus/);
 
     const hasTrapError = new Error('signature has trap');
     assert.throws(() => {
       lib.getFunction('add_i32', new Proxy({}, {
         has(target, key) {
-          if (key === 'result') {
+          if (key === 'return') {
             throw hasTrapError;
           }
           return Reflect.has(target, key);
@@ -339,8 +323,8 @@ test('dynamic library APIs validate failures and bad signatures', () => {
     const getterError = new Error('signature getter');
     assert.throws(() => {
       lib.getFunction('add_i32', {
-        result: 'i32',
-        get parameters() {
+        return: 'i32',
+        get arguments() {
           throw getterError;
         },
       });
diff --git a/test/ffi/test-ffi-shared-buffer.js b/test/ffi/test-ffi-shared-buffer.js
index 944b4021abc47a..429faf6439faf0 100644
--- a/test/ffi/test-ffi-shared-buffer.js
+++ b/test/ffi/test-ffi-shared-buffer.js
@@ -19,8 +19,8 @@ const { internalBinding } = require('internal/test/binding');
 const ffiBinding = internalBinding('ffi');
 const {
   kSbInvokeSlow,
-  kSbParams,
-  kSbResult,
+  kSbArguments,
+  kSbReturn,
   kSbSharedBuffer,
 } = ffiBinding;
 const rawGetFunctionUnpatched = ffiBinding.DynamicLibrary.prototype.getFunction;
@@ -30,7 +30,7 @@ const { libraryPath } = require('./ffi-test-common');
 
 test('numeric-only i32 function uses SB path', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
+    add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
   });
   try {
     assert.strictEqual(functions.add_i32(20, 22), 42);
@@ -44,10 +44,10 @@ test('numeric-only i32 function uses SB path', () => {
 
 test('i8/u8/i16/u16 round-trip', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_i8: { result: 'i8', parameters: ['i8', 'i8'] },
-    add_u8: { result: 'u8', parameters: ['u8', 'u8'] },
-    add_i16: { result: 'i16', parameters: ['i16', 'i16'] },
-    add_u16: { result: 'u16', parameters: ['u16', 'u16'] },
+    add_i8: { return: 'i8', arguments: ['i8', 'i8'] },
+    add_u8: { return: 'u8', arguments: ['u8', 'u8'] },
+    add_i16: { return: 'i16', arguments: ['i16', 'i16'] },
+    add_u16: { return: 'u16', arguments: ['u16', 'u16'] },
   });
   try {
     assert.strictEqual(functions.add_i8(10, 20), 30);
@@ -61,8 +61,8 @@ test('i8/u8/i16/u16 round-trip', () => {
 
 test('f32/f64 round-trip', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_f32: { result: 'f32', parameters: ['f32', 'f32'] },
-    add_f64: { result: 'f64', parameters: ['f64', 'f64'] },
+    add_f32: { return: 'f32', arguments: ['f32', 'f32'] },
+    add_f64: { return: 'f64', arguments: ['f64', 'f64'] },
   });
   try {
     // 1.25 and 2.75 are exactly representable in float32, so the sum is exact.
@@ -75,8 +75,8 @@ test('f32/f64 round-trip', () => {
 
 test('i64/u64 BigInt round-trip', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_i64: { result: 'i64', parameters: ['i64', 'i64'] },
-    add_u64: { result: 'u64', parameters: ['u64', 'u64'] },
+    add_i64: { return: 'i64', arguments: ['i64', 'i64'] },
+    add_u64: { return: 'u64', arguments: ['u64', 'u64'] },
   });
   try {
     assert.strictEqual(functions.add_i64(10n, 20n), 30n);
@@ -88,7 +88,7 @@ test('i64/u64 BigInt round-trip', () => {
 
 test('zero-arg function', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    char_is_signed: { result: 'i32', parameters: [] },
+    char_is_signed: { return: 'i32', arguments: [] },
   });
   try {
     const result = functions.char_is_signed();
@@ -101,7 +101,7 @@ test('zero-arg function', () => {
 
 test('6-arg numeric function', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    sum_6_i32: { result: 'i32', parameters: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32'] },
+    sum_6_i32: { return: 'i32', arguments: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32'] },
   });
   try {
     assert.strictEqual(functions.sum_6_i32(1, 2, 3, 4, 5, 6), 21);
@@ -112,8 +112,8 @@ test('6-arg numeric function', () => {
 
 test('pointer args: fast path (BigInt/null) and slow-path fallback (Buffer/ArrayBuffer)', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    identity_pointer: { result: 'pointer', parameters: ['pointer'] },
-    pointer_to_usize: { result: 'u64', parameters: ['pointer'] },
+    identity_pointer: { return: 'pointer', arguments: ['pointer'] },
+    pointer_to_usize: { return: 'u64', arguments: ['pointer'] },
   });
   try {
     assert.strictEqual(functions.identity_pointer(0n), 0n);
@@ -137,7 +137,7 @@ test('pointer args: fast path (BigInt/null) and slow-path fallback (Buffer/Array
 
 test('string pointer uses slow-path fallback', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    string_length: { result: 'u64', parameters: ['pointer'] },
+    string_length: { return: 'u64', arguments: ['pointer'] },
   });
   try {
     assert.strictEqual(functions.string_length('hello'), 5n);
@@ -150,8 +150,8 @@ test('string pointer uses slow-path fallback', () => {
 
 test('non-SB-eligible signature falls back to raw function', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    string_duplicate: { result: 'pointer', parameters: ['pointer'] },
-    free_string: { result: 'void', parameters: ['pointer'] },
+    string_duplicate: { return: 'pointer', arguments: ['pointer'] },
+    free_string: { return: 'void', arguments: ['pointer'] },
   });
   try {
     const dup = functions.string_duplicate('round-trip');
@@ -167,14 +167,14 @@ test('reentrancy across two FFI symbols', () => {
   // A JS callback invoked by one FFI function reenters a different FFI
   // function. Each has its own ArrayBuffer; neither may clobber the other.
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    call_int_callback: { result: 'i32', parameters: ['pointer', 'i32'] },
-    add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
+    call_int_callback: { return: 'i32', arguments: ['pointer', 'i32'] },
+    add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
   });
 
   let callDepth = 0;
   let innerResult = -1;
   const callback = lib.registerCallback(
-    { result: 'i32', parameters: ['i32'] },
+    { return: 'i32', arguments: ['i32'] },
     (x) => {
       callDepth++;
       if (callDepth === 1) innerResult = functions.add_i32(x, 100);
@@ -194,7 +194,7 @@ test('reentrancy across two FFI symbols', () => {
 
 test('arity mismatch throws ERR_INVALID_ARG_VALUE', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
+    add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
   });
   try {
     assert.throws(() => functions.add_i32(1), {
@@ -213,8 +213,8 @@ test('arity mismatch throws ERR_INVALID_ARG_VALUE', () => {
 test('arity 7+ uses the generic rest-params branch', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
     sum_7_i32: {
-      result: 'i32',
-      parameters: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
+      return: 'i32',
+      arguments: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
     },
   });
   try {
@@ -230,8 +230,8 @@ test('arity 7+ uses the generic rest-params branch', () => {
 
 test('wrappers preserve name/length/pointer and the functions accessor returns wrappers', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
-    identity_pointer: { result: 'pointer', parameters: ['pointer'] },
+    add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
+    identity_pointer: { return: 'pointer', arguments: ['pointer'] },
   });
   try {
     assert.strictEqual(functions.add_i32.name, 'add_i32');
@@ -253,12 +253,12 @@ test('wrappers preserve name/length/pointer and the functions accessor returns w
 
 test('integer boundaries for i8/u8/i16/u16/i32/u32', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_i8: { result: 'i8', parameters: ['i8', 'i8'] },
-    add_u8: { result: 'u8', parameters: ['u8', 'u8'] },
-    add_i16: { result: 'i16', parameters: ['i16', 'i16'] },
-    add_u16: { result: 'u16', parameters: ['u16', 'u16'] },
-    add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
-    add_u32: { result: 'u32', parameters: ['u32', 'u32'] },
+    add_i8: { return: 'i8', arguments: ['i8', 'i8'] },
+    add_u8: { return: 'u8', arguments: ['u8', 'u8'] },
+    add_i16: { return: 'i16', arguments: ['i16', 'i16'] },
+    add_u16: { return: 'u16', arguments: ['u16', 'u16'] },
+    add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
+    add_u32: { return: 'u32', arguments: ['u32', 'u32'] },
   });
 
   try {
@@ -299,8 +299,8 @@ test('integer boundaries for i8/u8/i16/u16/i32/u32', () => {
 
 test('i64/u64 BigInt boundaries and Number/BigInt type mismatches', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_i64: { result: 'i64', parameters: ['i64', 'i64'] },
-    add_u64: { result: 'u64', parameters: ['u64', 'u64'] },
+    add_i64: { return: 'i64', arguments: ['i64', 'i64'] },
+    add_u64: { return: 'u64', arguments: ['u64', 'u64'] },
   });
 
   try {
@@ -328,8 +328,8 @@ test('i64/u64 BigInt boundaries and Number/BigInt type mismatches', () => {
 
 test('char type picks signed/unsigned range based on host ABI', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    char_is_signed: { result: 'i32', parameters: [] },
-    identity_char: { result: 'char', parameters: ['char'] },
+    char_is_signed: { return: 'i32', arguments: [] },
+    identity_char: { return: 'char', arguments: ['char'] },
   });
 
   try {
@@ -358,13 +358,13 @@ test('SB metadata is Symbol-keyed, attribute-hardened, and not leaked onto the w
   const rawLib = new ffiBinding.DynamicLibrary(libraryPath);
   try {
     const rawFn = rawGetFunctionUnpatched.call(
-      rawLib, 'add_i32', { result: 'i32', parameters: ['i32', 'i32'] });
+      rawLib, 'add_i32', { return: 'i32', arguments: ['i32', 'i32'] });
 
     for (const [name, sym] of [
       ['kSbSharedBuffer', kSbSharedBuffer],
       ['kSbInvokeSlow', kSbInvokeSlow],
-      ['kSbParams', kSbParams],
-      ['kSbResult', kSbResult],
+      ['kSbArguments', kSbArguments],
+      ['kSbReturn', kSbReturn],
     ]) {
       assert.strictEqual(typeof sym, 'symbol', `${name} must be a Symbol`);
     }
@@ -372,8 +372,8 @@ test('SB metadata is Symbol-keyed, attribute-hardened, and not leaked onto the w
     // Numeric-only signature: kSbInvokeSlow absent; the rest present and hardened.
     for (const [name, sym] of [
       ['kSbSharedBuffer', kSbSharedBuffer],
-      ['kSbParams', kSbParams],
-      ['kSbResult', kSbResult],
+      ['kSbArguments', kSbArguments],
+      ['kSbReturn', kSbReturn],
     ]) {
       const desc = Object.getOwnPropertyDescriptor(rawFn, sym);
       assert.ok(desc !== undefined, `${name} missing on pure-numeric SB function`);
@@ -386,7 +386,7 @@ test('SB metadata is Symbol-keyed, attribute-hardened, and not leaked onto the w
 
     // Pointer signature: kSbInvokeSlow must exist (and be hardened).
     const rawPtrFn = rawGetFunctionUnpatched.call(
-      rawLib, 'identity_pointer', { result: 'pointer', parameters: ['pointer'] });
+      rawLib, 'identity_pointer', { return: 'pointer', arguments: ['pointer'] });
     const slowDesc = Object.getOwnPropertyDescriptor(rawPtrFn, kSbInvokeSlow);
     assert.ok(slowDesc !== undefined);
     assert.strictEqual(slowDesc.enumerable, false);
@@ -396,18 +396,18 @@ test('SB metadata is Symbol-keyed, attribute-hardened, and not leaked onto the w
     assert.deepStrictEqual(Object.keys(rawFn), ['pointer']);
     const ownSyms = Object.getOwnPropertySymbols(rawFn);
     assert.ok(ownSyms.includes(kSbSharedBuffer));
-    assert.ok(ownSyms.includes(kSbParams));
-    assert.ok(ownSyms.includes(kSbResult));
+    assert.ok(ownSyms.includes(kSbArguments));
+    assert.ok(ownSyms.includes(kSbReturn));
 
     // Internals must not be forwarded by `inheritMetadata`.
     const { lib, functions } = ffi.dlopen(libraryPath, {
-      add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
+      add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
     });
     try {
       assert.strictEqual(functions.add_i32[kSbSharedBuffer], undefined);
       assert.strictEqual(functions.add_i32[kSbInvokeSlow], undefined);
-      assert.strictEqual(functions.add_i32[kSbParams], undefined);
-      assert.strictEqual(functions.add_i32[kSbResult], undefined);
+      assert.strictEqual(functions.add_i32[kSbArguments], undefined);
+      assert.strictEqual(functions.add_i32[kSbReturn], undefined);
     } finally {
       lib.close();
     }
@@ -418,7 +418,7 @@ test('SB metadata is Symbol-keyed, attribute-hardened, and not leaked onto the w
 
 test('pointer fast-path range check: [0, 2^64 - 1]', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    identity_pointer: { result: 'pointer', parameters: ['pointer'] },
+    identity_pointer: { return: 'pointer', arguments: ['pointer'] },
   });
   try {
     assert.strictEqual(functions.identity_pointer(0n), 0n);
@@ -438,15 +438,15 @@ test('self-recursive reentrancy: a single function\'s ArrayBuffer survives a nes
   // call can reuse the same buffer without clobbering the outer frame.
   const { lib, functions } = ffi.dlopen(libraryPath, {
     call_binary_int_callback: {
-      result: 'i32',
-      parameters: ['function', 'i32', 'i32'],
+      return: 'i32',
+      arguments: ['function', 'i32', 'i32'],
     },
   });
 
   try {
     let depth = 0;
     const callback = lib.registerCallback(
-      { result: 'i32', parameters: ['i32', 'i32'] },
+      { return: 'i32', arguments: ['i32', 'i32'] },
       common.mustCall((a, b) => {
         depth++;
         if (depth === 1) {
@@ -469,9 +469,9 @@ test('self-recursive reentrancy: a single function\'s ArrayBuffer survives a nes
 
 test('void-return 0-arg wrapper branch', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    reset_counter: { result: 'void', parameters: [] },
-    increment_counter: { result: 'void', parameters: [] },
-    get_counter: { result: 'i32', parameters: [] },
+    reset_counter: { return: 'void', arguments: [] },
+    increment_counter: { return: 'void', arguments: [] },
+    get_counter: { return: 'i32', arguments: [] },
   });
   try {
     assert.strictEqual(functions.reset_counter(), undefined);
@@ -496,26 +496,26 @@ test('void-return wrapper at every specialized arity observes side effects', ()
   // at every arity the ladder specializes (1..6) plus the 7+ rest-params
   // fallback.
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    store_i32: { result: 'void', parameters: ['i32'] },
-    store_sum_2_i32: { result: 'void', parameters: ['i32', 'i32'] },
-    store_sum_3_i32: { result: 'void', parameters: ['i32', 'i32', 'i32'] },
+    store_i32: { return: 'void', arguments: ['i32'] },
+    store_sum_2_i32: { return: 'void', arguments: ['i32', 'i32'] },
+    store_sum_3_i32: { return: 'void', arguments: ['i32', 'i32', 'i32'] },
     store_sum_4_i32: {
-      result: 'void',
-      parameters: ['i32', 'i32', 'i32', 'i32'],
+      return: 'void',
+      arguments: ['i32', 'i32', 'i32', 'i32'],
     },
     store_sum_5_i32: {
-      result: 'void',
-      parameters: ['i32', 'i32', 'i32', 'i32', 'i32'],
+      return: 'void',
+      arguments: ['i32', 'i32', 'i32', 'i32', 'i32'],
     },
     store_sum_6_i32: {
-      result: 'void',
-      parameters: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
+      return: 'void',
+      arguments: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
     },
     store_sum_8_i32: {
-      result: 'void',
-      parameters: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
+      return: 'void',
+      arguments: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
     },
-    get_scratch: { result: 'i32', parameters: [] },
+    get_scratch: { return: 'i32', arguments: [] },
   });
   try {
     // Powers-of-two summands detect a dropped or duplicated slot at each
@@ -598,17 +598,17 @@ test('value-return wrapper arity mismatch hits every specialized branch', () =>
   // value-return closures for arities 1..6 so each specialization's
   // argument-count guard runs at least once.
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    logical_not: { result: 'i32', parameters: ['i32'] },
-    add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
-    sum_3_i32: { result: 'i32', parameters: ['i32', 'i32', 'i32'] },
-    sum_4_i32: { result: 'i32', parameters: ['i32', 'i32', 'i32', 'i32'] },
+    logical_not: { return: 'i32', arguments: ['i32'] },
+    add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
+    sum_3_i32: { return: 'i32', arguments: ['i32', 'i32', 'i32'] },
+    sum_4_i32: { return: 'i32', arguments: ['i32', 'i32', 'i32', 'i32'] },
     sum_five_i32: {
-      result: 'i32',
-      parameters: ['i32', 'i32', 'i32', 'i32', 'i32'],
+      return: 'i32',
+      arguments: ['i32', 'i32', 'i32', 'i32', 'i32'],
     },
     sum_6_i32: {
-      result: 'i32',
-      parameters: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
+      return: 'i32',
+      arguments: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32'],
     },
   });
   try {
@@ -647,7 +647,7 @@ test('pointer-dispatch wrapper rejects wrong-arity calls', () => {
   // per-arity ladder, but it still has its own `throwFFIArgCountError`
   // branch that needs to be exercised.
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    identity_pointer: { result: 'pointer', parameters: ['pointer'] },
+    identity_pointer: { return: 'pointer', arguments: ['pointer'] },
   });
   try {
     assert.throws(
@@ -669,10 +669,10 @@ test('pointer-dispatch wrapper rejects wrong-arity calls', () => {
 
 test('mid-arity wrappers (1, 3, 4, 5)', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    logical_not: { result: 'i32', parameters: ['i32'] },
-    sum_3_i32: { result: 'i32', parameters: ['i32', 'i32', 'i32'] },
-    sum_4_i32: { result: 'i32', parameters: ['i32', 'i32', 'i32', 'i32'] },
-    sum_five_i32: { result: 'i32', parameters: ['i32', 'i32', 'i32', 'i32', 'i32'] },
+    logical_not: { return: 'i32', arguments: ['i32'] },
+    sum_3_i32: { return: 'i32', arguments: ['i32', 'i32', 'i32'] },
+    sum_4_i32: { return: 'i32', arguments: ['i32', 'i32', 'i32', 'i32'] },
+    sum_five_i32: { return: 'i32', arguments: ['i32', 'i32', 'i32', 'i32', 'i32'] },
   });
   try {
     assert.strictEqual(functions.logical_not(0), 1);
@@ -689,8 +689,8 @@ test('mid-arity wrappers (1, 3, 4, 5)', () => {
 
 test('float specials: NaN, ±Infinity, -0 round-trip bit-exact', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    add_f64: { result: 'f64', parameters: ['f64', 'f64'] },
-    multiply_f64: { result: 'f64', parameters: ['f64', 'f64'] },
+    add_f64: { return: 'f64', arguments: ['f64', 'f64'] },
+    multiply_f64: { return: 'f64', arguments: ['f64', 'f64'] },
   });
   try {
     assert.ok(Number.isNaN(functions.add_f64(NaN, 1.0)));
@@ -704,7 +704,7 @@ test('float specials: NaN, ±Infinity, -0 round-trip bit-exact', () => {
 
 test('arity-7+ branch still runs per-arg validation', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    sum_7_i32: { result: 'i32', parameters: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32'] },
+    sum_7_i32: { return: 'i32', arguments: ['i32', 'i32', 'i32', 'i32', 'i32', 'i32', 'i32'] },
   });
   try {
     assert.throws(
@@ -720,7 +720,7 @@ test('mixed-kind signature (i32, f32, f64, u32) dispatches the right writer per
   // Four distinct `sbTypeInfo.kind` values (int, float, float, int) — a
   // wiring bug that reused one writer across slots would surface here.
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    mixed_operation: { parameters: ['i32', 'f32', 'f64', 'u32'], result: 'f64' },
+    mixed_operation: { arguments: ['i32', 'f32', 'f64', 'u32'], return: 'f64' },
   });
 
   try {
@@ -748,11 +748,11 @@ test('lib.getFunctions() with no arguments wraps every cached function', () => {
   // the early-return path in `wrapWithSharedBuffer` alongside the wrapped
   // branch.
   const { lib } = ffi.dlopen(libraryPath, {
-    add_i32: { result: 'i32', parameters: ['i32', 'i32'] },
-    add_f64: { result: 'f64', parameters: ['f64', 'f64'] },
-    mixed_operation: { parameters: ['i32', 'f32', 'f64', 'u32'], result: 'f64' },
-    identity_pointer: { result: 'pointer', parameters: ['pointer'] },
-    string_length: { result: 'u64', parameters: ['string'] },
+    add_i32: { return: 'i32', arguments: ['i32', 'i32'] },
+    add_f64: { return: 'f64', arguments: ['f64', 'f64'] },
+    mixed_operation: { arguments: ['i32', 'f32', 'f64', 'u32'], return: 'f64' },
+    identity_pointer: { return: 'pointer', arguments: ['pointer'] },
+    string_length: { return: 'u64', arguments: ['string'] },
   });
 
   try {
@@ -789,12 +789,12 @@ test('lib.getFunctions() with no arguments wraps every cached function', () => {
 
 test('mixed pointer + numeric signature uses the pointer-dispatch wrapper', () => {
   const { lib, functions } = ffi.dlopen(libraryPath, {
-    call_int_callback: { result: 'i32', parameters: ['pointer', 'i32'] },
+    call_int_callback: { return: 'i32', arguments: ['pointer', 'i32'] },
   });
 
   try {
     const cb = lib.registerCallback(
-      { result: 'i32', parameters: ['i32'] },
+      { return: 'i32', arguments: ['i32'] },
       (x) => x * 2,
     );
     try {
diff --git a/test/ffi/test-ffi-weakref-calls.js b/test/ffi/test-ffi-weakref-calls.js
index d29ca1051fa450..1a2a2eaeab87cd 100644
--- a/test/ffi/test-ffi-weakref-calls.js
+++ b/test/ffi/test-ffi-weakref-calls.js
@@ -15,7 +15,7 @@ test('ffi unrefCallback releases callback function', async (t) => {
   let callback = () => 1;
   const ref = new WeakRef(callback);
   const pointer = lib.registerCallback(
-    { parameters: ['i32'], result: 'i32' },
+    { arguments: ['i32'], return: 'i32' },
     callback,
   );
 
@@ -37,7 +37,7 @@ test('ffi refCallback retains callback function', async (t) => {
 
   let callback = () => 1;
   const ref = new WeakRef(callback);
-  const pointer = lib.registerCallback({ result: 'i32' }, callback);
+  const pointer = lib.registerCallback({ return: 'i32' }, callback);
 
   lib.unrefCallback(pointer);
   lib.refCallback(pointer);