openapi: 3.0.3
info:
  title: Words Categories Hierarchy API
  version: 1.0.0
  description: 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. Authentication is handled via the RapidAPI marketplace using the X-RapidAPI-Key and X-RapidAPI-Host headers.
  contact:
    name: Words API Support
    email: support@wordsapi.com
    url: https://www.wordsapi.com/
  license:
    name: Words API Terms of Service
    url: https://www.wordsapi.com/
  x-generated-from: documentation
  x-last-validated: '2026-05-30'
servers:
- url: https://wordsapiv1.p.rapidapi.com
  description: Words API production endpoint, served through the RapidAPI gateway.
security:
- RapidApiKey: []
tags:
- name: Hierarchy
  description: Words API Lexical Hierarchies — typeOf, hasTypes, partOf, hasParts, instances.
paths:
  /words/{word}/hasTypes:
    get:
      tags:
      - Hierarchy
      operationId: getHasTypes
      summary: Get Word Has Types
      description: Returns the more specific words (hyponyms) of the given word.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: hasTypes returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HasTypesResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/typeOf:
    get:
      tags:
      - Hierarchy
      operationId: getTypeOf
      summary: Get Word Type Of
      description: Returns the more generic words (hypernyms) of the given word.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: typeOf returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TypeOfResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/partOf:
    get:
      tags:
      - Hierarchy
      operationId: getPartOf
      summary: Get Word Part Of
      description: Returns wholes the word is a part of (holonyms).
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: partOf returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PartOfResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/hasParts:
    get:
      tags:
      - Hierarchy
      operationId: getHasParts
      summary: Get Word Has Parts
      description: Returns the parts that compose the word (meronyms).
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: hasParts returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HasPartsResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/instances:
    get:
      tags:
      - Hierarchy
      operationId: getInstances
      summary: Get Word Instances
      description: Returns specific instances of the given word (e.g. concrete examples of a category).
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: instances returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/InstancesResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/instanceOf:
    get:
      tags:
      - Hierarchy
      operationId: getInstanceOf
      summary: Get Word Instance Of
      description: Returns the categories of which the given word is an instance.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: instanceOf returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/InstanceOfResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/entails:
    get:
      tags:
      - Hierarchy
      operationId: getEntails
      summary: Get Word Entails
      description: Returns words logically entailed by the given word, typically verbs.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: entails returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/EntailsResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/memberOf:
    get:
      tags:
      - Hierarchy
      operationId: getMemberOf
      summary: Get Word Member Of
      description: Returns groups the given word is a member of.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: memberOf returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MemberOfResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/hasMembers:
    get:
      tags:
      - Hierarchy
      operationId: getHasMembers
      summary: Get Word Has Members
      description: Returns the members that belong to the given group word.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: hasMembers returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HasMembersResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/substanceOf:
    get:
      tags:
      - Hierarchy
      operationId: getSubstanceOf
      summary: Get Word Substance Of
      description: Returns materials of which the given word is a substance.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: substanceOf returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SubstanceOfResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /words/{word}/hasSubstances:
    get:
      tags:
      - Hierarchy
      operationId: getHasSubstances
      summary: Get Word Has Substances
      description: Returns the substances that compose the given word.
      parameters:
      - $ref: '#/components/parameters/Word'
      responses:
        '200':
          description: hasSubstances returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HasSubstancesResponse'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
components:
  schemas:
    InstancesResponse:
      type: object
      properties:
        word:
          type: string
        instances:
          type: array
          items:
            type: string
    SubstanceOfResponse:
      type: object
      properties:
        word:
          type: string
        substanceOf:
          type: array
          items:
            type: string
    InstanceOfResponse:
      type: object
      properties:
        word:
          type: string
        instanceOf:
          type: array
          items:
            type: string
    MemberOfResponse:
      type: object
      properties:
        word:
          type: string
        memberOf:
          type: array
          items:
            type: string
    PartOfResponse:
      type: object
      properties:
        word:
          type: string
          example: wheel
        partOf:
          type: array
          items:
            type: string
          example:
          - car
          - bicycle
    HasSubstancesResponse:
      type: object
      properties:
        word:
          type: string
        hasSubstances:
          type: array
          items:
            type: string
    HasPartsResponse:
      type: object
      properties:
        word:
          type: string
          example: car
        hasParts:
          type: array
          items:
            type: string
          example:
          - wheel
          - engine
          - door
    HasTypesResponse:
      type: object
      properties:
        word:
          type: string
          example: fruit
        hasTypes:
          type: array
          items:
            type: string
          example:
          - apple
          - orange
          - pear
    EntailsResponse:
      type: object
      properties:
        word:
          type: string
          example: walk
        entails:
          type: array
          items:
            type: string
          example:
          - step
          - move
    HasMembersResponse:
      type: object
      properties:
        word:
          type: string
        hasMembers:
          type: array
          items:
            type: string
    TypeOfResponse:
      type: object
      properties:
        word:
          type: string
          example: apple
        typeOf:
          type: array
          items:
            type: string
          example:
          - edible fruit
          - pome
          - false fruit
  parameters:
    Word:
      name: word
      in: path
      required: true
      description: The English word to look up.
      schema:
        type: string
      example: apple
  securitySchemes:
    RapidApiKey:
      type: apiKey
      in: header
      name: X-RapidAPI-Key
      description: RapidAPI subscription key. The X-RapidAPI-Host header (wordsapiv1.p.rapidapi.com) is also required.