"topic" meaning in English

{
  "forms": [
    {
      "form": "topic",
      "tags": [
        "singular"
      ]
    },
    {
      "form": "topics",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "expansion": "[POS TABLE]",
      "name": "noun"
    }
  ],
  "hyphenation": "top‧ic",
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [],
      "examples": [
        {
          "text": "We were talking about my problems. Don't change the topic."
        },
        {
          "text": "Our library has books on a wide range of topics."
        },
        {
          "text": "When you're writing for school, it's important to stay on topic, and not start talking about other things."
        }
      ],
      "glosses": [
        "A topic is a general idea that someone is speaking (reading, thinking, etc.) about at a specific time."
      ],
      "id": "simple-topic-en-noun-tX6yNtsY",
      "raw_tags": [
        "countable"
      ],
      "synonyms": [
        {
          "word": "theme"
        },
        {
          "word": "subject"
        }
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈtɒpɪk/",
      "tags": [
        "UK"
      ]
    },
    {
      "ipa": "/ˈtɑpɪk/",
      "tags": [
        "US"
      ]
    },
    {
      "audio": "en-us-topic.ogg",
      "tags": [
        "US"
      ]
    }
  ],
  "word": "topic"
}

{
  "forms": [
    {
      "form": "topic",
      "tags": [
        "singular"
      ]
    },
    {
      "form": "topics",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "expansion": "[POS TABLE]",
      "name": "noun"
    }
  ],
  "hyphenation": "top‧ic",
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Countable nouns"
      ],
      "examples": [
        {
          "text": "We were talking about my problems. Don't change the topic."
        },
        {
          "text": "Our library has books on a wide range of topics."
        },
        {
          "text": "When you're writing for school, it's important to stay on topic, and not start talking about other things."
        }
      ],
      "glosses": [
        "A topic is a general idea that someone is speaking (reading, thinking, etc.) about at a specific time."
      ],
      "raw_tags": [
        "countable"
      ],
      "synonyms": [
        {
          "word": "theme"
        },
        {
          "word": "subject"
        }
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈtɒpɪk/",
      "tags": [
        "UK"
      ]
    },
    {
      "ipa": "/ˈtɑpɪk/",
      "tags": [
        "US"
      ]
    },
    {
      "audio": "en-us-topic.ogg",
      "tags": [
        "US"
      ]
    }
  ],
  "word": "topic"
}