Dictionaries — entry 012 of 12

Words

Verified Jul 2026

WordsAPI is a RapidAPI-hosted REST dictionary/thesaurus returning JSON definitions, synonyms, antonyms, rhymes, pronunciations, and word-frequency data across more than 150,000 English words — its own docs still show code samples calling the deprecated `wordsapiv1.p.mashape.com` host with an `X-Mashape-Key` header, but that legacy domain now refuses every request and a current RapidAPI key against the live `.p.rapidapi.com` proxy is required instead. A live unauthenticated request against that real proxy host returned a reflected `access-control-allow-origin` header plus `access-control-allow-credentials: true`, confirming CORS; its free tier covers 2,500 requests/day before paid plans starting at $10/month raise the ceiling to 25,000+/day.

dictionarysynonymsrapidapiword-lookupenglish
AuthenticationAPI KeySign up with the provider to obtain credentials.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreemiumA usable free tier exists, with paid plans for more volume.
FormatsJSONResponses can be requested as JSON.

GreatAPIs Score

Score61out of 100
Authentication15/25API key required
Pricing17/20Freemium tier available
Docs0/20No docs or spec available
Formats9/15Single response format
Freshness20/20Verified within 6 months

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Scored 61 on greatapis.com
<a href="https://greatapis.com/api/words/"><img src="https://greatapis.com/badge/words.svg" alt="Scored 61 on greatapis.com"></a>

Auth quickstart

  1. Sign up with the provider to get an API key.
  2. Send it on every request as a headerAuthorization: <key>
  3. The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Stored keyNo key stored

Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.