# Merriam-Webster API: Define word

> Looks up a word or phrase in Merriam-Webster's dictionary and returns its pronunciation, definitions, examples and word history.

Unofficial. Not affiliated with or endorsed by Merriam-Webster.

- Page: https://fous.com/methods/merriam-webster.com/define-word
- Method: `merriam-webster.com/define_word`, version 1
- Website: merriam-webster.com
- Returns: headword, pronunciation, audio link, page link, entries with definitions, examples, etymology, first known use
- Effect: read (it gets data and changes nothing)
- Sign-in: none needed
- Cost: 1 credit per completed run (1¢ with pay as you go); failed runs are free
- Verified: Nov 2, 2026

## Inputs

| Field | Type | Required | In the run below | Description |
|---|---|---|---|---|
| `word` | string | yes | `"run"` | The word or phrase to look up, for example serendipity. |

## Output

From a run on Oct 23, 2026, shortened. Its input:

```json
{
  "word": "run"
}
```

Its output:

```json
{
  "word": "run",
  "entries": [
    {
      "etymology": "Middle English ronnen, alteration of rinnen, intransitive verb (from Old English iernan, rinnan & Old Norse rinna ) & of rennen, transitive verb, from Old Norse renna; akin to Old High German rinnan, intransitive verb, \"to run,\" Sanskrit riṇāti \"he causes to flow,\" and probably to Latin rivus \"strea…",
      "definitions": [
        "intransitive verb 1a. to go faster than a walk",
        "intransitive verb 1a. specifically: to go steadily by springing steps so that both feet leave the ground for an instant in each step",
        "intransitive verb 1b. of a horse: to move at a fast gallop"
      ],
      "part_of_speech": "verb",
      "first_known_use": "before the 12th century",
      "example_sentences": [
        "When they heard the alarm ring, they ran.",
        "let chickens run loose",
        "a ram running with ewes"
      ]
    },
    {
      "etymology": null,
      "definitions": [
        "1a. an act or the action of running : continued rapid movement",
        "1b. a quickened gallop",
        "1c. a migration of fish (as up or down a river) especially to spawn"
      ],
      "part_of_speech": "noun",
      "first_known_use": "15th century",
      "example_sentences": [
        "goes out for a run every morning",
        "When the robbers heard the alarm, they made a run for it. [=they ran away to avoid capture]",
        "The dogs were coming toward us at a run. [=the dogs were running toward us]"
      ]
    },
    {
      "etymology": null,
      "definitions": [
        "1a. being in a melted state",
        "1b. made from molten material : cast in a mold",
        "2. of fish: having made a migration or spawning run"
      ],
      "part_of_speech": "adjective",
      "first_known_use": "1685",
      "example_sentences": [
        "run butter",
        "run metal",
        "a fresh run salmon"
      ]
    }
  ],
  "pronunciation": "ˈrən",
  "merriam_webster_link": "https://www.merriam-webster.com/dictionary/run",
  "pronunciation_audio_link": "https://media.merriam-webster.com/audio/prons/en/us/mp3/r/run00001.mp3"
}
```

## Run it

From code, with a Fous API key in `FOUS_API_KEY`; the answer's `data` holds the output:

```bash
curl https://api.fous.com/v1/runs \
  -H "Authorization: Bearer $FOUS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"method":"merriam-webster.com/define_word","input":{"word":"run"}}'
```

From an AI agent connected to the Fous MCP server: its `run` with the same method and input. To connect one, give it `set up https://fous.com/SKILL.md`.

## Ask your agent

- What does the word serendipity mean, and when was it first used in English?
- Can you give me the pronunciation and an audio clip for the word ephemeral?
- Look up 'ubiquitous' and show me its definitions with example sentences.
- I need the etymology and first known use of the phrase 'raison d'etre' from Merriam-Webster.
- Find the dictionary entries for 'lackadaisical' including part of speech and usage examples.

## Input schema

```json
{
  "type": "object",
  "required": [
    "word"
  ],
  "properties": {
    "word": {
      "type": "string",
      "minLength": 1,
      "description": "The word or phrase to look up, for example serendipity."
    }
  }
}
```

## Output schema

```json
{
  "type": "object",
  "required": [
    "word",
    "merriam_webster_link",
    "entries"
  ],
  "properties": {
    "word": {
      "type": "string"
    },
    "entries": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "etymology": {
            "type": [
              "string",
              "null"
            ]
          },
          "definitions": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "part_of_speech": {
            "type": "string"
          },
          "first_known_use": {
            "type": [
              "string",
              "null"
            ]
          },
          "example_sentences": {
            "type": "array",
            "items": {
              "type": "string"
            }
          }
        }
      }
    },
    "pronunciation": {
      "type": [
        "string",
        "null"
      ]
    },
    "merriam_webster_link": {
      "type": "string"
    },
    "pronunciation_audio_link": {
      "type": [
        "string",
        "null"
      ]
    }
  }
}
```

## See more

- [Merriam-Webster API: Get synonyms](https://fous.com/methods/merriam-webster.com/get-synonyms.md): Looks up a word on its public Merriam-Webster thesaurus page and returns each meaning with its example, synonyms, antonyms and related words.
- [Merriam-Webster API: Get Merriam-Webster Word of the Day](https://fous.com/methods/merriam-webster.com/get-word-of-the-day.md): Gets Merriam-Webster's Word of the Day for today or a past archive date, with its meaning, example, pronunciation and background note. Dates without a published entry are unavailable.
- [Dictionary.com API: Define word](https://fous.com/methods/dictionary.com/define-word.md): Looks up an English word on Dictionary.com and returns its pronunciation, audio link, numbered definitions per dialect with examples, word origin and first recorded use.
- [Cambridge University Press API: Define word](https://fous.com/methods/dictionary.cambridge.org/define-word.md): Looks up a word or phrase on Cambridge Dictionary and returns its ordered meanings, example sentences, grammar labels and UK and US pronunciations.
- [Dictionary.com API: Get synonyms](https://fous.com/methods/dictionary.com/get-synonyms.md): Gets a word's Thesaurus.com meanings in site order, with part of speech, short meaning, synonyms and antonyms ranked strongest, strong or weak.
- [Etymonline API: Get word origin](https://fous.com/methods/etymonline.com/get-word-origin.md): Looks up an English word on Etymonline and returns its origin entries, one per part of speech, with the first date mentioned and cross-referenced words.
- [WordReference API: Translate word](https://fous.com/methods/wordreference.com/translate-word.md): Translates a word or phrase between languages using WordReference, including usage notes, example sentences and compound forms when shown. Only language pairs listed by WordReference are available.
- [Cambridge University Press API: Translate word](https://fous.com/methods/dictionary.cambridge.org/translate-word.md): Translates a word between English and a language Cambridge supports. Returns the meanings, the translations and any paired examples.
- [All Merriam-Webster methods](https://fous.com/methods/merriam-webster.com.md)