"fever fog" meaning in English

{
  "forms": [
    {
      "form": "fever fogs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "fever fog (plural fever fogs)",
      "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": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1886 October – 1887 January, H[enry] Rider Haggard, She: A History of Adventure, London: Longmans, Green, and Co., published 1887, →OCLC:",
          "text": "Miles on miles of quagmire, varied only by bright green strips of comparatively solid ground, and by deep and sullen pools fringed with tall rushes, in which the bitterns boomed and the frogs croaked incessantly: miles on miles of it without a break, unless the fever fog can be called a break.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Any mist rising from swampy ground, formerly believed to cause fever; a miasma."
      ],
      "id": "en-fever_fog-en-noun-41UAJxta",
      "links": [
        [
          "mist",
          "mist"
        ],
        [
          "swampy",
          "swampy"
        ],
        [
          "fever",
          "fever"
        ],
        [
          "miasma",
          "miasma"
        ]
      ]
    }
  ],
  "word": "fever fog"
}

{
  "forms": [
    {
      "form": "fever fogs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "fever fog (plural fever fogs)",
      "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",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "1886 October – 1887 January, H[enry] Rider Haggard, She: A History of Adventure, London: Longmans, Green, and Co., published 1887, →OCLC:",
          "text": "Miles on miles of quagmire, varied only by bright green strips of comparatively solid ground, and by deep and sullen pools fringed with tall rushes, in which the bitterns boomed and the frogs croaked incessantly: miles on miles of it without a break, unless the fever fog can be called a break.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Any mist rising from swampy ground, formerly believed to cause fever; a miasma."
      ],
      "links": [
        [
          "mist",
          "mist"
        ],
        [
          "swampy",
          "swampy"
        ],
        [
          "fever",
          "fever"
        ],
        [
          "miasma",
          "miasma"
        ]
      ]
    }
  ],
  "word": "fever fog"
}