"fever blister" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fever",
        "3": "blister"
      },
      "expansion": "fever + blister",
      "name": "com"
    }
  ],
  "etymology_text": "From fever + blister, likely for an association with fever or other illness.",
  "forms": [
    {
      "form": "fever blisters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "fever blister (plural fever blisters)",
      "name": "en-noun"
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  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
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        }
      ],
      "glosses": [
        "A cold sore, an outbreak of vesicles caused by herpes simplex viral infection, especially when recurring during another illness that causes fever."
      ],
      "id": "en-fever_blister-en-noun-y6piIODH",
      "links": [
        [
          "cold sore",
          "cold sore"
        ],
        [
          "vesicle",
          "vesicle"
        ],
        [
          "herpes simplex",
          "herpes simplex"
        ],
        [
          "fever",
          "fever"
        ]
      ]
    }
  ],
  "word": "fever blister"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fever",
        "3": "blister"
      },
      "expansion": "fever + blister",
      "name": "com"
    }
  ],
  "etymology_text": "From fever + blister, likely for an association with fever or other illness.",
  "forms": [
    {
      "form": "fever blisters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "fever blister (plural fever blisters)",
      "name": "en-noun"
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  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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        "English compound terms",
        "English countable nouns",
        "English entries with incorrect language header",
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      ],
      "glosses": [
        "A cold sore, an outbreak of vesicles caused by herpes simplex viral infection, especially when recurring during another illness that causes fever."
      ],
      "links": [
        [
          "cold sore",
          "cold sore"
        ],
        [
          "vesicle",
          "vesicle"
        ],
        [
          "herpes simplex",
          "herpes simplex"
        ],
        [
          "fever",
          "fever"
        ]
      ]
    }
  ],
  "word": "fever blister"
}