"bitter cold" meaning in English

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  "etymology_text": "Coined by William Shakespeare in 1602 in \"Hamlet,\" act 1, scene 1:\n: For this relief much thanks. 'Tis bitter cold,\n: And I am sick at heart.",
  "head_templates": [
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      "expansion": "bitter cold",
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  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
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        {
          "kind": "topical",
          "langcode": "en",
          "name": "Temperature",
          "orig": "en:Temperature",
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            "Nature",
            "Weather",
            "All topics",
            "Atmosphere",
            "Fundamental"
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      ],
      "glosses": [
        "Very cold and unpleasant. (of an environment)"
      ],
      "id": "en-bitter_cold-en-phrase-DW4vBbNo",
      "links": [
        [
          "cold",
          "cold"
        ],
        [
          "unpleasant",
          "unpleasant"
        ],
        [
          "environment",
          "environment"
        ]
      ],
      "synonyms": [
        {
          "tags": [
            "proscribed"
          ],
          "word": "bitterly cold"
        }
      ]
    }
  ],
  "word": "bitter cold"
}

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  ],
  "etymology_text": "Coined by William Shakespeare in 1602 in \"Hamlet,\" act 1, scene 1:\n: For this relief much thanks. 'Tis bitter cold,\n: And I am sick at heart.",
  "head_templates": [
    {
      "args": {
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      "expansion": "bitter cold",
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  "lang_code": "en",
  "pos": "phrase",
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        "Very cold and unpleasant. (of an environment)"
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        [
          "cold",
          "cold"
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        [
          "unpleasant",
          "unpleasant"
        ],
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          "environment",
          "environment"
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      ]
    }
  ],
  "synonyms": [
    {
      "tags": [
        "proscribed"
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      "word": "bitterly cold"
    }
  ],
  "word": "bitter cold"
}