"78" meaning in English

{
  "forms": [
    {
      "form": "78s",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "78's",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "s",
        "2": "78's"
      },
      "expansion": "78 (plural 78s or 78's)",
      "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 retronyms",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2009, Jennifer Worth, Farewell to the East End, Weidenfeld & Nicholson, page 273",
          "text": "She swallowed hard, and her arm jerked sideways, knocking over a table lamp, which fell onto the record player, where our favourite 78 was spinning round.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A gramophone record played at 78 revolutions per minute."
      ],
      "id": "en-78-en-noun-DiE9f24b",
      "links": [
        [
          "gramophone",
          "gramophone"
        ],
        [
          "record",
          "record"
        ]
      ],
      "raw_glosses": [
        "(retronym) A gramophone record played at 78 revolutions per minute."
      ],
      "tags": [
        "retronym"
      ]
    }
  ],
  "word": "78"
}

{
  "forms": [
    {
      "form": "78s",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "78's",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "s",
        "2": "78's"
      },
      "expansion": "78 (plural 78s or 78's)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English nouns with irregular plurals",
        "English retronyms",
        "English terms spelled with numbers",
        "English terms with quotations",
        "English words without vowels"
      ],
      "examples": [
        {
          "ref": "2009, Jennifer Worth, Farewell to the East End, Weidenfeld & Nicholson, page 273",
          "text": "She swallowed hard, and her arm jerked sideways, knocking over a table lamp, which fell onto the record player, where our favourite 78 was spinning round.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A gramophone record played at 78 revolutions per minute."
      ],
      "links": [
        [
          "gramophone",
          "gramophone"
        ],
        [
          "record",
          "record"
        ]
      ],
      "raw_glosses": [
        "(retronym) A gramophone record played at 78 revolutions per minute."
      ],
      "tags": [
        "retronym"
      ]
    }
  ],
  "word": "78"
}