"lightning bug" meaning in English

{
  "forms": [
    {
      "form": "lightning bugs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "lightning bug (plural lightning bugs)",
      "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": "lifeform",
          "langcode": "en",
          "name": "Elateroid beetles",
          "orig": "en:Elateroid beetles",
          "parents": [
            "Beetles",
            "Insects",
            "Arthropods",
            "Animals",
            "Lifeforms",
            "All topics",
            "Life",
            "Fundamental",
            "Nature"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Light sources",
          "orig": "en:Light sources",
          "parents": [
            "Light",
            "Energy",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2019, Ta-Nehisi Coates, The Water Dancer, Penguin Books (2020), page 18",
          "text": "I watched as lightning bugs drifted in, glowing yellow against the shadows.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A firefly."
      ],
      "id": "en-lightning_bug-en-noun-png6mfpB",
      "links": [
        [
          "firefly",
          "firefly"
        ]
      ]
    }
  ],
  "word": "lightning bug"
}

{
  "forms": [
    {
      "form": "lightning bugs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "lightning bug (plural lightning bugs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "en:Elateroid beetles",
        "en:Light sources"
      ],
      "examples": [
        {
          "ref": "2019, Ta-Nehisi Coates, The Water Dancer, Penguin Books (2020), page 18",
          "text": "I watched as lightning bugs drifted in, glowing yellow against the shadows.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A firefly."
      ],
      "links": [
        [
          "firefly",
          "firefly"
        ]
      ]
    }
  ],
  "word": "lightning bug"
}