English dictionary API: word definitions from Wiktionary

$0.01 per call · failed calls are never charged · no account or subscription: pay per call with a card key or USDC

Dictionary definition of an English word from Wiktionary, grouped by part of speech, with example sentences where Wiktionary gives them, plus the page link and the CC BY-SA attribution to show. Use for writing help, vocabulary, translation checks and word games.

When to use it

Look up definitions of an English word grouped by part of speech
Get example sentences where Wiktionary gives them
Writing help, vocabulary, translation checks and word games

Run it free (25 free calls) Buy credits by card (from $1) Example result (JSON)

Inputs

Name	Type	Description
`word` (required)	string	An English word

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://tools.funwords.eu/dictionary?word=serendipity"

Or one of your 25 free calls, no key:

curl "https://tools.funwords.eu/dictionary?word=serendipity&trial=1"

Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum or Solana over x402; Base or Tempo over MPP) and retries.

Example result

{
  "word": "serendipity",
  "meanings": [
    {
      "partOfSpeech": "Noun",
      "definitions": [
        {
          "definition": "An unsought, unintended, and/or unexpected, but fortunate, discovery.",
          "example": null
        }
      ]
    }
  ],
  "url": "https://en.wiktionary.org/wiki/serendipity",
  "licence": "CC BY-SA 4.0",
  "attribution": "Definitions from the Wiktionary entry \"serendipity\" by its contributors, licensed CC BY-SA 4.0"
}

From an AI agent (MCP)

Add the MCP server to Claude, Cursor or any MCP client. This tool is dictionary, and the first 25 successful calls are free:

https://tools.funwords.eu/mcp

Questions

Where do the definitions come from?

Wiktionary, with the page link and the CC BY-SA attribution to show.

Which languages?

English words only.

How do I pay?

Each successful call costs $0.01; failed calls are not charged. The first 25 calls are free. Then pay with card credits (from $1; the key goes in an Authorization header or, for clients that can only fetch a URL, as api_key= in the URL) or per call in USDC over x402 or MPP. No account is needed.