"red alert" meaning in English

{
  "forms": [
    {
      "form": "red alerts",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "red alert (countable and uncountable, plural red alerts)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [],
      "examples": [
        {
          "ref": "1944 August 7, Charles A. Lindbergh, The Wartime Journals of Charles A. Lindbergh, New York: Harcourt Brace Jovanovich, published 1970, page 898",
          "text": "Another red alert last night. Lasted only five minutes, Possibly just a friendly plane with its IFF turned off.",
          "type": "quotation"
        },
        {
          "ref": "1984, Nena, 99 Red Balloons (lyrics written by Kevin McAlea)",
          "text": "Ninety-nine red balloons\nFloating in the summer sky\nPanic bells, it's red alert\nThere's something here from somewhere else"
        }
      ],
      "glosses": [
        "A warning that indicates an emergency situation."
      ],
      "id": "en-red_alert-en-noun-cUv-iHyB",
      "tags": [
        "countable",
        "uncountable"
      ]
    },
    {
      "categories": [
        {
          "_dis": "27 73",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "A state of readiness to deal with such emergency situation."
      ],
      "id": "en-red_alert-en-noun-UWzh8uEi",
      "related": [
        {
          "_dis1": "25 75",
          "word": "alarums and excursions"
        },
        {
          "_dis1": "25 75",
          "tags": [
            "UK"
          ],
          "word": "panic stations"
        }
      ],
      "synonyms": [
        {
          "_dis1": "42 58",
          "word": "battle stations"
        },
        {
          "_dis1": "42 58",
          "tags": [
            "Navy",
            "US"
          ],
          "word": "general quarters"
        },
        {
          "_dis1": "42 58",
          "tags": [
            "Navy",
            "UK"
          ],
          "word": "action stations"
        }
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-ɜː(ɹ)t"
    },
    {
      "audio": "En-us-red alert.oga",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/5/5c/En-us-red_alert.oga/En-us-red_alert.oga.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/5/5c/En-us-red_alert.oga",
      "tags": [
        "US"
      ],
      "text": "Audio (US)"
    }
  ],
  "wikipedia": [
    "red alert"
  ],
  "word": "red alert"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns",
    "English terms with audio links",
    "English uncountable nouns",
    "Rhymes:English/ɜː(ɹ)t",
    "Rhymes:English/ɜː(ɹ)t/3 syllables"
  ],
  "forms": [
    {
      "form": "red alerts",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "red alert (countable and uncountable, plural red alerts)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "alarums and excursions"
    },
    {
      "tags": [
        "UK"
      ],
      "word": "panic stations"
    }
  ],
  "senses": [
    {
      "categories": [
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "1944 August 7, Charles A. Lindbergh, The Wartime Journals of Charles A. Lindbergh, New York: Harcourt Brace Jovanovich, published 1970, page 898",
          "text": "Another red alert last night. Lasted only five minutes, Possibly just a friendly plane with its IFF turned off.",
          "type": "quotation"
        },
        {
          "ref": "1984, Nena, 99 Red Balloons (lyrics written by Kevin McAlea)",
          "text": "Ninety-nine red balloons\nFloating in the summer sky\nPanic bells, it's red alert\nThere's something here from somewhere else"
        }
      ],
      "glosses": [
        "A warning that indicates an emergency situation."
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    },
    {
      "glosses": [
        "A state of readiness to deal with such emergency situation."
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-ɜː(ɹ)t"
    },
    {
      "audio": "En-us-red alert.oga",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/5/5c/En-us-red_alert.oga/En-us-red_alert.oga.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/5/5c/En-us-red_alert.oga",
      "tags": [
        "US"
      ],
      "text": "Audio (US)"
    }
  ],
  "synonyms": [
    {
      "word": "battle stations"
    },
    {
      "tags": [
        "Navy",
        "US"
      ],
      "word": "general quarters"
    },
    {
      "tags": [
        "Navy",
        "UK"
      ],
      "word": "action stations"
    }
  ],
  "wikipedia": [
    "red alert"
  ],
  "word": "red alert"
}