"llysfab" meaning in Gallois

{
  "categories": [
    {
      "kind": "other",
      "name": "Dérivations en gallois",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Lexique en gallois de la famille",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Mots en gallois préfixés avec llys-",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Noms communs en gallois",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Gallois",
      "orig": "gallois",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "Dérivé de mab (« fils »), avec le préfixe llys-.",
    "Apparenté au breton lezvab."
  ],
  "forms": [
    {
      "form": "llysfeibion",
      "tags": [
        "plural",
        "unmutated"
      ]
    },
    {
      "form": "lysfab",
      "raw_tags": [
        "Lénition"
      ],
      "tags": [
        "singular"
      ]
    },
    {
      "form": "lysfeibion",
      "raw_tags": [
        "Lénition"
      ],
      "tags": [
        "plural"
      ]
    },
    {
      "form": "llysferch",
      "source": "form line template 'équiv-pour'",
      "tags": [
        "feminine"
      ]
    }
  ],
  "lang": "Gallois",
  "lang_code": "cy",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "glosses": [
        "Beau-fils (après second mariage)."
      ],
      "id": "fr-llysfab-cy-noun-JAI6qoFI"
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "llysfab"
}

{
  "categories": [
    "Dérivations en gallois",
    "Lexique en gallois de la famille",
    "Mots en gallois préfixés avec llys-",
    "Noms communs en gallois",
    "gallois"
  ],
  "etymology_texts": [
    "Dérivé de mab (« fils »), avec le préfixe llys-.",
    "Apparenté au breton lezvab."
  ],
  "forms": [
    {
      "form": "llysfeibion",
      "tags": [
        "plural",
        "unmutated"
      ]
    },
    {
      "form": "lysfab",
      "raw_tags": [
        "Lénition"
      ],
      "tags": [
        "singular"
      ]
    },
    {
      "form": "lysfeibion",
      "raw_tags": [
        "Lénition"
      ],
      "tags": [
        "plural"
      ]
    },
    {
      "form": "llysferch",
      "source": "form line template 'équiv-pour'",
      "tags": [
        "feminine"
      ]
    }
  ],
  "lang": "Gallois",
  "lang_code": "cy",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "glosses": [
        "Beau-fils (après second mariage)."
      ]
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "llysfab"
}