Words API

Words API is a RESTful English-language API that provides definitions, synonyms, antonyms, related words, syllables, pronunciation (IPA), rhymes, frequency, and hierarchical lexical relationships (typeOf, hasTypes, partOf, hasParts, memberOf, similarTo, also, entails, inCategory, inRegion, pertainsTo, etc.) for more than 150,000 English words. Distributed and metered through the RapidAPI marketplace.

1 APIs 11 Features

DictionariesLinguisticsEnglishThesaurusLexical DataPublic APIs

APIs

Words API

RESTful English-language dictionary, thesaurus, and lexical-relationship API. One base resource — /words/{word} — plus 28 sub-resources for individual detail types (definitions,...

Collections

Words API

OPEN

Pricing Plans

Words Plans Pricing

5 plans

PLANS

Rate Limits

Words Rate Limits

5 limits

RATE LIMITS

FinOps

Words Finops

FINOPS

Features

150,000+ English Words

Definitions, syllables, pronunciation, and lexical relationships across more than 150,000 English words.

Definitions and Parts of Speech

Per-sense definitions grouped by part of speech (noun, verb, adjective, adverb).

Thesaurus (Synonyms and Antonyms)

Interchangeable and opposite-meaning words for each sense of a word.

Lexical Hierarchies

typeOf, hasTypes, partOf, hasParts, instanceOf, hasInstances, memberOf, hasMembers, substanceOf, hasSubstances, inCategory, hasCategories relationships.

Pronunciation in IPA

International Phonetic Alphabet pronunciation, optionally split per part of speech.

Syllable Breakdown

Syllable count and the ordered list of syllables for each word.

Rhymes

Lists of rhyming words, distinguished by pronunciation variant where pronunciations differ.

Frequency Data

Zipf frequency (1–7), per-million occurrence rate, and corpus diversity score derived from large English subtitle corpora.

Examples

Sample sentences illustrating real usage for each sense.

Regional and Domain Usage

inRegion, regionOf, inCategory, hasCategories, usageOf, hasUsages relationships connect words to dialects and subject domains.

Random and Filtered Word Search

/words search endpoint supports letter count, letter pattern, phoneme count, IPA pattern, part of speech, and random selection.

Use Cases

Dictionary and Thesaurus Applications

Power dictionary, thesaurus, and "word of the day" applications with definitions, synonyms, and related words.

Word Games and Puzzles

Drive crossword, Scrabble-style, and anagram games with filtered word search, rhymes, and difficulty-tunable random word selection.

Writing and Editing Tools

Build grammar, style, and writing assistants that suggest synonyms, antonyms, and frequency-aware alternatives.

Language Learning and Education

Provide IPA pronunciation, syllable splits, frequency, and example sentences for ESL and vocabulary-building apps.

NLP and Text Enrichment

Enrich downstream NLP pipelines with hypernyms, hyponyms, meronyms, and domain labels for entity expansion.

Voice and Speech Applications

Use IPA pronunciation and syllable data for speech synthesis, ASR vocabulary tuning, and pronunciation coaching.

Chatbots and Conversational Agents

Disambiguate user input by mapping words to their senses, hypernyms, and categories at runtime.

Content Generation and Rewriting

Drive paraphrasing and content-variation engines with synonym, similar-to, and pertains-to relationships.

Integrations

RapidAPI

Words API is distributed, authenticated, and metered through the RapidAPI marketplace.

WordNet

Lexical relationships (typeOf, hasParts, memberOf, etc.) follow the WordNet relational model.

Subtitle Corpora

Frequency data is derived from large English movie and television subtitle corpora (see WordsAPI/wordfrequencies on GitHub).

Solutions

Free Tier

2,500 requests per day at no charge for prototyping, students, and small projects.

Pro

$10 / month, 25,000 requests per day for production applications and games.

Ultra

$49 / month, 250,000 requests per day for high-volume consumer applications.

Mega

$89 / month, 500,000 requests per day for very high-volume production workloads.

Data Purchase

One-time $629 purchase of the full Words API dataset for local hosting.

Semantic Vocabularies

Words Context

36 classes · 48 properties

JSON-LD

API Governance Rules

Words API API Rules

32 rules · 13 errors 18 warnings 1 info

5 properties

5 fields

EXAMPLE

Resources

GitHubOrganization

GitHubOrganization

👥

Word Frequencies Dataset

PublicAPIsListing

Sources

opencollection: 1.0.0
info:
  name: Words API
  version: 1.0.0
request:
  auth:
    type: apikey
    key: X-RapidAPI-Key
    value: '{{X-RapidAPI-Key}}'
    placement: header
items:
- info:
    name: Word
    type: folder
  items:
  - info:
      name: Get Word Entry
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Retrieves the full lexical entry for a single English word — every documented sense (definition + part of speech),
      syllable breakdown, IPA pronunciation, and the embedded results array used by every other detail-type endpoint.
- info:
    name: Definitions
    type: folder
  items:
  - info:
      name: Get Word Definitions
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/definitions
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns every documented definition for the word, grouped by part of speech.
- info:
    name: Thesaurus
    type: folder
  items:
  - info:
      name: Get Word Synonyms
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/synonyms
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns words interchangeable with the given word in the same sense.
  - info:
      name: Get Word Antonyms
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/antonyms
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns opposite-meaning words for the given word.
  - info:
      name: Get Words Similar To
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/similar
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns related but non-synonymous words for the given word.
  - info:
      name: Get Word Also Used
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/also
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns idiomatic phrases that include the given word.
- info:
    name: Examples
    type: folder
  items:
  - info:
      name: Get Word Examples
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/examples
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns example sentences that use the given word.
- info:
    name: Phonetics
    type: folder
  items:
  - info:
      name: Get Word Rhymes
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/rhymes
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns words that rhyme with the given word, organized by part of speech when pronunciations differ.
  - info:
      name: Get Word Syllables
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/syllables
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the syllable count and the ordered list of syllables for the word.
  - info:
      name: Get Word Pronunciation
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/pronunciation
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the IPA pronunciation for the word, optionally split by part of speech.
- info:
    name: Frequency
    type: folder
  items:
  - info:
      name: Get Word Frequency
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/frequency
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns corpus-derived frequency statistics for the word — Zipf score (1–7), per-million occurrence rate, and corpus
      diversity (0–1).
- info:
    name: Hierarchy
    type: folder
  items:
  - info:
      name: Get Word Has Types
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/hasTypes
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the more specific words (hyponyms) of the given word.
  - info:
      name: Get Word Type Of
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/typeOf
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the more generic words (hypernyms) of the given word.
  - info:
      name: Get Word Part Of
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/partOf
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns wholes the word is a part of (holonyms).
  - info:
      name: Get Word Has Parts
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/hasParts
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the parts that compose the word (meronyms).
  - info:
      name: Get Word Instances
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/instances
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns specific instances of the given word (e.g. concrete examples of a category).
  - info:
      name: Get Word Instance Of
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/instanceOf
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the categories of which the given word is an instance.
  - info:
      name: Get Word Entails
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/entails
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns words logically entailed by the given word, typically verbs.
  - info:
      name: Get Word Member Of
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/memberOf
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns groups the given word is a member of.
  - info:
      name: Get Word Has Members
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/hasMembers
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the members that belong to the given group word.
  - info:
      name: Get Word Substance Of
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/substanceOf
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns materials of which the given word is a substance.
  - info:
      name: Get Word Has Substances
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/hasSubstances
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the substances that compose the given word.
- info:
    name: Categories
    type: folder
  items:
  - info:
      name: Get Word In Category
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/inCategory
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the categories the given word belongs to.
  - info:
      name: Get Word Has Categories
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/hasCategories
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the subcategories of the given category word.
  - info:
      name: Get Word Usage Of
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/usageOf
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the domain-usage classifications of the given word.
  - info:
      name: Get Word Has Usages
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/hasUsages
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the domain-usage examples of the given word.
  - info:
      name: Get Word In Region
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/inRegion
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the geographic regions where the given word is used.
  - info:
      name: Get Word Region Of
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/regionOf
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns the regional variants associated with the given word.
  - info:
      name: Get Word Pertains To
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/:word/pertainsTo
      params:
      - name: word
        value: apple
        type: path
        description: The English word to look up.
    docs: Returns words to which the given word pertains (adjective-to-noun and similar relations).
- info:
    name: Search
    type: folder
  items:
  - info:
      name: Search Words and Get Random Word
      type: http
    http:
      method: GET
      url: https://wordsapiv1.p.rapidapi.com/words/
      params:
      - name: letterPattern
        value: ^a.*z$
        type: query
        description: Regex pattern matched against the word's letters.
      - name: letters
        value: '5'
        type: query
        description: Exact letter count.
      - name: lettersMin
        value: '4'
        type: query
        description: Minimum letter count.
      - name: lettersMax
        value: '10'
        type: query
        description: Maximum letter count.
      - name: pronunciationPattern
        value: ˈæp.*
        type: query
        description: Regex pattern matched against the IPA pronunciation.
      - name: sounds
        value: '5'
        type: query
        description: Exact phoneme count.
      - name: soundsMin
        value: '3'
        type: query
        description: Minimum phoneme count.
      - name: soundsMax
        value: '8'
        type: query
        description: Maximum phoneme count.
      - name: partOfSpeech
        value: verb
        type: query
        description: Filter by grammatical class.
      - name: hasDetails
        value: synonyms,examples
        type: query
        description: Comma-separated detail types the word must have (e.g. "synonyms
      - name: random
        value: 'true'
        type: query
        description: Return a single random word matching the filters.
      - name: limit
        value: '50'
        type: query
        description: Results per page (1–100).
      - name: page
        value: '1'
        type: query
        description: Page number for pagination.
    docs: Searches the Words API dictionary using letter, sound, part-of-speech, and detail-type filters. Pass random=true
      to return a single random word matching the filters.
bundled: true