"degree day" meaning in English

{
  "forms": [
    {
      "form": "degree days",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "degree day (plural degree days)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "glosses": [
        "A measure of heating or cooling, computed as the integral of a function of time that generally varies with temperature."
      ],
      "id": "en-degree_day-en-noun-PU9aHj9F"
    },
    {
      "categories": [
        {
          "_dis": "38 62",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "derived": [
        {
          "_dis1": "0 100",
          "word": "cooling degree day"
        },
        {
          "_dis1": "0 100",
          "word": "heating degree day"
        }
      ],
      "glosses": [
        "A unit used in estimating the fuel consumption for a building; equal to the number of degrees that the mean temperature, for a 24-hour day, is below the base temperature, often 65F."
      ],
      "id": "en-degree_day-en-noun-zrJOdAK6",
      "links": [
        [
          "unit",
          "unit"
        ],
        [
          "fuel",
          "fuel"
        ]
      ],
      "translations": [
        {
          "_dis1": "0 100",
          "code": "fi",
          "lang": "Finnish",
          "sense": "unit",
          "word": "astepäivä"
        }
      ]
    }
  ],
  "word": "degree day"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns"
  ],
  "derived": [
    {
      "word": "cooling degree day"
    },
    {
      "word": "heating degree day"
    }
  ],
  "forms": [
    {
      "form": "degree days",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "degree day (plural degree days)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "glosses": [
        "A measure of heating or cooling, computed as the integral of a function of time that generally varies with temperature."
      ]
    },
    {
      "glosses": [
        "A unit used in estimating the fuel consumption for a building; equal to the number of degrees that the mean temperature, for a 24-hour day, is below the base temperature, often 65F."
      ],
      "links": [
        [
          "unit",
          "unit"
        ],
        [
          "fuel",
          "fuel"
        ]
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "unit",
      "word": "astepäivä"
    }
  ],
  "word": "degree day"
}