Dictionary API

The Dictionary API provides programmatic access to definitions, synonyms, antonyms, pronunciations, and translations for over 15 million words across 100+ languages. Built for developers, educators, and linguists who need fast, accurate, and scalable language data.

Base URL https://api.dictionary.com/v1

Quick Start

Include your API key in the request header and make your first call:

Request Example

curl -X GET "https://api.dictionary.com/v1/definitions?word=ephemeral" \
  -H "X-API-Key: your_api_key_here" \
  -H "Accept: application/json"

💡 Tip: All responses are served over HTTPS. The API uses JSON for both request and response payloads.

Authentication

Access to the Dictionary API requires an API key. Include your key in the X-API-Key header for every request. Never expose your API key in client-side code.

Authentication Header

X-API-Key: sk_dict_9x8y7z6w5v4u3t2s1r0q

⚠️ Security Notice: Rotate your API keys regularly and restrict key permissions to specific endpoints when possible.

Endpoints

GET /definitions

Retrieve definitions, examples, and part-of-speech tags for a specific word.

GET /v1/definitions?word={word}&lang={lang}

Query Parameters

Parameter	Type	Required	Description
`word`	string	Yes	The word to look up (max 50 chars)
`lang`	string	No	Language code (default: `en`)
`limit`	integer	No	Max results to return (default: 5, max: 20)

Response Example

200 OK

{
  "word": "ephemeral",
  "phonetic": "/əˈfem.ər.əl/",
  "definitions": [
    {
      "partOfSpeech": "adjective",
      "definition": "Lasting for a very short time; transitory.",
      "example": "The ephemeral beauty of cherry blossoms reminds us to cherish every moment.",
      "synonyms": ["fleeting", "transient", "momentary"]
    }
  ]
}

GET /synonyms

Fetch contextual synonyms and antonyms for a given word.

GET /v1/synonyms?word={word}&context={part_of_speech}

Response

{
  "word": "happy",
  "synonyms": ["joyful", "cheerful", "elated", "content"],
  "antonyms": ["sad", "miserable", "depressed"],
  "usage_notes": "Best used in informal or descriptive contexts."
}

POST /translate

Translate text between supported languages with context-aware results.

POST /v1/translate

Request Body

{
  "text": "The quick brown fox jumps over the lazy dog.",
  "source_lang": "en",
  "target_lang": "es",
  "preserve_formatting": true
}

Response

{
  "translated_text": "El rápido zorro marrón salta sobre el perro perezoso.",
  "source_lang": "en",
  "target_lang": "es",
  "confidence": 0.98
}

Status Codes

The API uses standard HTTP status codes to indicate success or failure.

200

Success. Request processed correctly.

400

Bad request. Invalid parameters or malformed JSON.

401

Unauthorized. Invalid or missing API key.

403

Forbidden. Key lacks permissions for endpoint.

429

Rate limit exceeded. Slow down your requests.

500

Internal server error. Try again later.

Rate Limits

API requests are rate-limited based on your subscription plan. Limits are calculated per API key.

Plan	Requests / Minute	Daily Cap
Free	60	1,000
Pro	600	50,000
Enterprise	Custom	Custom

Rate Limit Headers: Response headers include X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset to help you track usage.

SDKs & Tools

Official SDKs are available for popular languages and frameworks. All SDKs handle authentication, retries, and rate limit backoff automatically.

Python JavaScript / Node.js Go Ruby Postman Collection

Need a different language? Request an SDK →