"water jacket" meaning in English

{
  "forms": [
    {
      "form": "water jackets",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "water jacket (plural water jackets)",
      "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"
        }
      ],
      "examples": [
        {
          "ref": "1949, American Railway Engineering Association, Bulletin - Issues 481-487, page 277",
          "text": "The headbolt heater consists of a hollow steel bolt containing an electric heating element. This device is designed to heat the water jacket and is applied to the engine head by replacing a headbolt.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "An enclosed space, or the walls used to create it, that surrounds an object to be heated or cooled by water flowing around it."
      ],
      "id": "en-water_jacket-en-noun-WDL1BGNX",
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "enclosed space",
          "word": "vesivaippa"
        }
      ],
      "wikipedia": [
        "water jacket"
      ]
    }
  ],
  "word": "water jacket"
}

{
  "forms": [
    {
      "form": "water jackets",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "water jacket (plural water jackets)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "1949, American Railway Engineering Association, Bulletin - Issues 481-487, page 277",
          "text": "The headbolt heater consists of a hollow steel bolt containing an electric heating element. This device is designed to heat the water jacket and is applied to the engine head by replacing a headbolt.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "An enclosed space, or the walls used to create it, that surrounds an object to be heated or cooled by water flowing around it."
      ],
      "wikipedia": [
        "water jacket"
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "enclosed space",
      "word": "vesivaippa"
    }
  ],
  "word": "water jacket"
}