"hard deck" meaning in English

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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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          "langcode": "en",
          "name": "Aviation",
          "orig": "en:Aviation",
          "parents": [
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      "examples": [
        {
          "ref": "1986, Top Gun",
          "text": "Get your butts above the hard deck. Return to base immediately.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "In air combat training, the minimum allowed altitude below which the aircraft is considered destroyed by ground impact."
      ],
      "id": "en-hard_deck-en-noun-CWoEUmzI",
      "links": [
        [
          "aviation",
          "aviation"
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      "raw_glosses": [
        "(aviation) In air combat training, the minimum allowed altitude below which the aircraft is considered destroyed by ground impact."
      ],
      "tags": [
        "uncountable"
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      "topics": [
        "aeronautics",
        "aerospace",
        "aviation",
        "business",
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  ],
  "word": "hard deck"
}

{
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      "expansion": "hard deck (uncountable)",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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        "en:Aviation"
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      "examples": [
        {
          "ref": "1986, Top Gun",
          "text": "Get your butts above the hard deck. Return to base immediately.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "In air combat training, the minimum allowed altitude below which the aircraft is considered destroyed by ground impact."
      ],
      "links": [
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          "aviation",
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        "(aviation) In air combat training, the minimum allowed altitude below which the aircraft is considered destroyed by ground impact."
      ],
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        "uncountable"
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      "topics": [
        "aeronautics",
        "aerospace",
        "aviation",
        "business",
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        "natural-sciences",
        "physical-sciences"
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  ],
  "word": "hard deck"
}