Dictionaries – Free-tier APIs
12 Free-tier APIs in the category Dictionaries. Free public web APIs that developers and AI agents can call. Entries come from the open public-apis list; each link was checked automatically (HTTP status) on the date shown, which says the site responded, not that the API is good.
Chinese Text Project
Online open-access digital library for pre-modern Chinese texts
Collins
Bilingual Dictionary and Thesaurus Data
Free Dictionary
Definitions, phonetics, pronunciations, parts of speech, examples, synonyms
Merriam-Webster
Dictionary and Thesaurus Data
Oxford
Dictionary Data
Random Lexicon
Random words and definitions using optional filters
SayItVid
English video pronunciation search with timestamps, IPA phonetics and subtitle context
Synonyms
Synonyms, thesaurus and antonyms information for any given word
Wiktionary
Collaborative dictionary data
Wordnik
Dictionary Data
Words
Definitions and synonyms for more than 150,000 words
WordSoHard
Word definitions with Scrabble validity and tile score in one call, built for word games