"fer-" meaning in Icelandic

{
  "categories": [
    {
      "_dis": "0 0",
      "kind": "other",
      "name": "Icelandic entries with incorrect language header",
      "parents": [
        "Entries with incorrect language header",
        "Entry maintenance"
      ],
      "source": "w+disamb"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "is",
        "2": "non",
        "3": "fer-"
      },
      "expansion": "Old Norse fer-",
      "name": "inh"
    },
    {
      "args": {
        "1": "is",
        "2": "gem-pro",
        "3": "*feþur-"
      },
      "expansion": "Proto-Germanic *feþur-",
      "name": "inh"
    },
    {
      "args": {
        "1": "is",
        "2": "ine-pro",
        "3": "*kʷetwr̥-"
      },
      "expansion": "Proto-Indo-European *kʷetwr̥-",
      "name": "inh"
    },
    {
      "args": {
        "1": "ine-pro",
        "2": "*kʷetwóres",
        "3": "",
        "4": "four"
      },
      "expansion": "*kʷetwóres (“four”)",
      "name": "m"
    }
  ],
  "etymology_text": "From Old Norse fer-, from Proto-Germanic *feþur-, from Proto-Indo-European *kʷetwr̥-, the zero-grade form of *kʷetwóres (“four”).",
  "head_templates": [
    {
      "args": {
        "1": "is",
        "2": "prefix"
      },
      "expansion": "fer-",
      "name": "head"
    }
  ],
  "lang": "Icelandic",
  "lang_code": "is",
  "pos": "prefix",
  "senses": [
    {
      "glosses": [
        "four, quadri-, tetra-"
      ],
      "id": "en-fer--is-prefix-eAhKK4Hq",
      "links": [
        [
          "four",
          "four"
        ],
        [
          "quadri-",
          "quadri-"
        ],
        [
          "tetra-",
          "tetra-"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    },
    {
      "glosses": [
        "square"
      ],
      "id": "en-fer--is-prefix-S6Po43Zf",
      "links": [
        [
          "square",
          "square"
        ]
      ],
      "raw_glosses": [
        "(in derived units) square"
      ],
      "raw_tags": [
        "in derived units"
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/fɛːr/"
    }
  ],
  "word": "fer-"
}

{
  "categories": [
    "Icelandic 1-syllable words",
    "Icelandic entries with incorrect language header",
    "Icelandic lemmas",
    "Icelandic prefixes",
    "Icelandic terms derived from Old Norse",
    "Icelandic terms derived from Proto-Germanic",
    "Icelandic terms derived from Proto-Indo-European",
    "Icelandic terms inherited from Old Norse",
    "Icelandic terms inherited from Proto-Germanic",
    "Icelandic terms inherited from Proto-Indo-European",
    "Icelandic terms with IPA pronunciation"
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "is",
        "2": "non",
        "3": "fer-"
      },
      "expansion": "Old Norse fer-",
      "name": "inh"
    },
    {
      "args": {
        "1": "is",
        "2": "gem-pro",
        "3": "*feþur-"
      },
      "expansion": "Proto-Germanic *feþur-",
      "name": "inh"
    },
    {
      "args": {
        "1": "is",
        "2": "ine-pro",
        "3": "*kʷetwr̥-"
      },
      "expansion": "Proto-Indo-European *kʷetwr̥-",
      "name": "inh"
    },
    {
      "args": {
        "1": "ine-pro",
        "2": "*kʷetwóres",
        "3": "",
        "4": "four"
      },
      "expansion": "*kʷetwóres (“four”)",
      "name": "m"
    }
  ],
  "etymology_text": "From Old Norse fer-, from Proto-Germanic *feþur-, from Proto-Indo-European *kʷetwr̥-, the zero-grade form of *kʷetwóres (“four”).",
  "head_templates": [
    {
      "args": {
        "1": "is",
        "2": "prefix"
      },
      "expansion": "fer-",
      "name": "head"
    }
  ],
  "lang": "Icelandic",
  "lang_code": "is",
  "pos": "prefix",
  "senses": [
    {
      "glosses": [
        "four, quadri-, tetra-"
      ],
      "links": [
        [
          "four",
          "four"
        ],
        [
          "quadri-",
          "quadri-"
        ],
        [
          "tetra-",
          "tetra-"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    },
    {
      "glosses": [
        "square"
      ],
      "links": [
        [
          "square",
          "square"
        ]
      ],
      "raw_glosses": [
        "(in derived units) square"
      ],
      "raw_tags": [
        "in derived units"
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/fɛːr/"
    }
  ],
  "word": "fer-"
}