"Vífilsborg" meaning in Vieux norrois

{
  "categories": [
    {
      "kind": "other",
      "name": "Noms propres en vieux norrois",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Vieux norrois",
      "orig": "vieux norrois",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Vieux norrois",
  "lang_code": "non",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "glosses": [
        "Avenches."
      ],
      "id": "fr-Vífilsborg-non-name-kpxQV503"
    }
  ],
  "word": "Vífilsborg"
}

{
  "categories": [
    "Noms propres en vieux norrois",
    "vieux norrois"
  ],
  "lang": "Vieux norrois",
  "lang_code": "non",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "glosses": [
        "Avenches."
      ]
    }
  ],
  "word": "Vífilsborg"
}