"death zone" meaning in English

{
  "forms": [
    {
      "form": "death zones",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "death zone (plural death zones)",
      "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": "Climbing",
          "orig": "en:Climbing",
          "parents": [
            "Sports",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2009 03, Ross Piper, Death Zone: Can Humans Survive at 26,000 Feet?, Capstone, page 10",
          "text": "That makes life even harder in the freezing temperatures of the death zone. High in the mountains the cold affects you quickly. You get goose bumps as your skin tries to trap warm air in the fine hairs that cover your body.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Land at sufficiently high altitudes that there is not enough oxygen to sustain human life."
      ],
      "id": "en-death_zone-en-noun-jl9Oi6-d",
      "links": [
        [
          "climbing",
          "climbing#Noun"
        ],
        [
          "altitude",
          "altitude"
        ],
        [
          "oxygen",
          "oxygen"
        ]
      ],
      "raw_glosses": [
        "(climbing) Land at sufficiently high altitudes that there is not enough oxygen to sustain human life."
      ],
      "related": [
        {
          "word": "Armstrong line"
        },
        {
          "word": "dead zone"
        },
        {
          "word": "Kármán line"
        },
        {
          "word": "kill zone"
        }
      ],
      "synonyms": [
        {
          "word": "lethal zone"
        },
        {
          "word": "Death Zone"
        }
      ],
      "topics": [
        "climbing",
        "hobbies",
        "lifestyle",
        "sports"
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "zone",
          "word": "kuolemanvyöhyke"
        },
        {
          "code": "de",
          "lang": "German",
          "sense": "zone",
          "tags": [
            "feminine"
          ],
          "word": "Todeszone"
        },
        {
          "code": "pl",
          "lang": "Polish",
          "note": "not idiomatic",
          "sense": "zone",
          "tags": [
            "feminine"
          ],
          "word": "strefa śmierci"
        }
      ],
      "wikipedia": [
        "death zone"
      ]
    }
  ],
  "word": "death zone"
}

{
  "forms": [
    {
      "form": "death zones",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "death zone (plural death zones)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "Armstrong line"
    },
    {
      "word": "dead zone"
    },
    {
      "word": "Kármán line"
    },
    {
      "word": "kill zone"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "en:Climbing"
      ],
      "examples": [
        {
          "ref": "2009 03, Ross Piper, Death Zone: Can Humans Survive at 26,000 Feet?, Capstone, page 10",
          "text": "That makes life even harder in the freezing temperatures of the death zone. High in the mountains the cold affects you quickly. You get goose bumps as your skin tries to trap warm air in the fine hairs that cover your body.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Land at sufficiently high altitudes that there is not enough oxygen to sustain human life."
      ],
      "links": [
        [
          "climbing",
          "climbing#Noun"
        ],
        [
          "altitude",
          "altitude"
        ],
        [
          "oxygen",
          "oxygen"
        ]
      ],
      "raw_glosses": [
        "(climbing) Land at sufficiently high altitudes that there is not enough oxygen to sustain human life."
      ],
      "synonyms": [
        {
          "word": "lethal zone"
        }
      ],
      "topics": [
        "climbing",
        "hobbies",
        "lifestyle",
        "sports"
      ],
      "wikipedia": [
        "death zone"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "Death Zone"
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "zone",
      "word": "kuolemanvyöhyke"
    },
    {
      "code": "de",
      "lang": "German",
      "sense": "zone",
      "tags": [
        "feminine"
      ],
      "word": "Todeszone"
    },
    {
      "code": "pl",
      "lang": "Polish",
      "note": "not idiomatic",
      "sense": "zone",
      "tags": [
        "feminine"
      ],
      "word": "strefa śmierci"
    }
  ],
  "word": "death zone"
}