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.
Inputs
Values from the run on Oct 23, 2026, shown under Output.
- Word, required
word The word or phrase to look up, for example serendipity.
run
Input as JSON
{ "word": "run"}Output
{ "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" }Code
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"}}' # Save as fous.py, then run: python3 fous.pyimport json, os, timefrom urllib.error import HTTPErrorfrom urllib.request import Request, urlopenAPI = "https://api.fous.com/v1/runs" KEY = os.environ["FOUS_API_KEY"]HEADERS = { "Authorization": f"Bearer {KEY}", "Content-Type": "application/json" ,}def call(url, body=None): data = json.dumps(body).encode() if body else None request = Request(url, data, HEADERS) try: with urlopen(request, timeout=120) as r: return r.status, json.load(r) except HTTPError as error: message = json.load(error)["error"]["message"] raise RuntimeError(message) from errorstatus, run = call(API, { "method": "merriam-webster.com/define_word" , "input": { "word": "run" }})# 202: still going after 30 s. Ask again until it ends.while status == 202: time.sleep(2) status, run = call(f"{API}/{run['id']}")print(json.dumps(run["data"], indent=2))// Save as fous.mjs, then run: node fous.mjsconst api = "https://api.fous.com/v1/runs" ;const headers = { Authorization: `Bearer ${process.env.FOUS_API_KEY}`, "Content-Type": "application/json" ,};let response = await fetch(api, { method: "POST", headers, body: JSON.stringify({ "method": "merriam-webster.com/define_word" , "input": { "word": "run" } }), signal: AbortSignal.timeout(120_000),});let run = await response.json();// 202: still going after 30 s. Ask again until it ends.while (response.status === 202) { await new Promise((done) => setTimeout(done, 2_000)); response = await fetch(`${api}/${run.id}`, { headers }); run = await response.json();}if (!response.ok) throw new Error(run.error.message);console.log(run.data);# Connect your agent to Fous once, over MCP (Streamable HTTP):# https://api.fous.com/mcp# Set FOUS_API_KEY first: create a key at https://app.fous.com/keys.# Claude Codeclaude mcp add \ --scope user \ --transport http fous https://api.fous.com/mcp \ --header "Authorization: Bearer ${FOUS_API_KEY:?Set FOUS_API_KEY to your Fous API key}"# Codexcodex mcp add fous \ --url https://api.fous.com/mcp \ --bearer-token-env-var FOUS_API_KEY# Cursor, VS Code, Windsurf, Cline and morenpx -y add-mcp https://api.fous.com/mcp -g -n fous \ --header "Authorization: Bearer ${FOUS_API_KEY:?Set FOUS_API_KEY to your Fous API key}"# Then ask your agent:# "Use Fous to run merriam-webster.com/define_word# with {"word":"run"}"Over HTTP, the answer’s data holds the output. A run still going after 30 seconds answers 202 with its id: ask GET /v1/runs/{id} until it ends.
Schema
Input schema
{ "type": "object", "required": [ "word" ], "properties": { "word": { "type": "string", "minLength": 1, "description": "The word or phrase to look up, for example serendipity." } }}Output schema
{ "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" ] } }}- Price
- 1 credit per completed run (1¢ with pay as you go); failed runs are free.
- Method
merriam-webster.com/define_word- Returns
- headword, pronunciation, audio link, page link, entries with definitions, examples, etymology, first known use
Use it from your agent
Give your agent this line. It reads SKILL.md, gets a Fous API key and connects the Fous MCP server. Its run then takes the method merriam-webster.com/define_word with the inputs above.
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.
See more
All Merriam-Webster methodsLooks up a word on its public Merriam-Webster thesaurus page and returns each meaning with its example, synonyms, antonyms and related words.
merriam-webster.com/get_synonymsGets 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.
merriam-webster.com/get_word_of_the_dayLooks 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.
dictionary.com/define_wordLooks up a word or phrase on Cambridge Dictionary and returns its ordered meanings, example sentences, grammar labels and UK and US pronunciations.
dictionary.cambridge.org/define_wordGets a word's Thesaurus.com meanings in site order, with part of speech, short meaning, synonyms and antonyms ranked strongest, strong or weak.
dictionary.com/get_synonymsLooks 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.
etymonline.com/get_word_originTranslates 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.
wordreference.com/translate_wordTranslates a word between English and a language Cambridge supports. Returns the meanings, the translations and any paired examples.
dictionary.cambridge.org/translate_word