"subtopic" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "sub",
        "3": "topic"
      },
      "expansion": "sub- + topic",
      "name": "prefix"
    }
  ],
  "etymology_text": "From sub- + topic.",
  "forms": [
    {
      "form": "subtopics",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "subtopic (plural subtopics)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with sub-",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "The meeting dragged on interminably as topics were divided into subtopics.",
          "type": "example"
        }
      ],
      "glosses": [
        "A subject that forms part of a topic."
      ],
      "id": "en-subtopic-en-noun-XCo8T2T3",
      "links": [
        [
          "topic",
          "topic"
        ]
      ],
      "related": [
        {
          "word": "supertopic"
        }
      ]
    }
  ],
  "word": "subtopic"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "sub",
        "3": "topic"
      },
      "expansion": "sub- + topic",
      "name": "prefix"
    }
  ],
  "etymology_text": "From sub- + topic.",
  "forms": [
    {
      "form": "subtopics",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "subtopic (plural subtopics)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "supertopic"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms prefixed with sub-",
        "English terms with usage examples"
      ],
      "examples": [
        {
          "text": "The meeting dragged on interminably as topics were divided into subtopics.",
          "type": "example"
        }
      ],
      "glosses": [
        "A subject that forms part of a topic."
      ],
      "links": [
        [
          "topic",
          "topic"
        ]
      ]
    }
  ],
  "word": "subtopic"
}