"stomach flu" meaning in English

{
  "forms": [
    {
      "form": "stomach flus",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "-",
        "2": "s"
      },
      "expansion": "stomach flu (usually uncountable, plural stomach flus)",
      "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": "topical",
          "langcode": "en",
          "name": "Pathology",
          "orig": "en:Pathology",
          "parents": [
            "Medicine",
            "Biology",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Gastroenteritis."
      ],
      "id": "en-stomach_flu-en-noun-1MJOBnYA",
      "links": [
        [
          "Gastroenteritis",
          "gastroenteritis"
        ]
      ],
      "raw_glosses": [
        "(informal, proscribed) Gastroenteritis."
      ],
      "tags": [
        "informal",
        "proscribed",
        "uncountable",
        "usually"
      ]
    }
  ],
  "word": "stomach flu"
}

{
  "forms": [
    {
      "form": "stomach flus",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "-",
        "2": "s"
      },
      "expansion": "stomach flu (usually uncountable, plural stomach flus)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English informal terms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English proscribed terms",
        "English uncountable nouns",
        "en:Pathology"
      ],
      "glosses": [
        "Gastroenteritis."
      ],
      "links": [
        [
          "Gastroenteritis",
          "gastroenteritis"
        ]
      ],
      "raw_glosses": [
        "(informal, proscribed) Gastroenteritis."
      ],
      "tags": [
        "informal",
        "proscribed",
        "uncountable",
        "usually"
      ]
    }
  ],
  "word": "stomach flu"
}