"zastumfet" meaning in Breton

{
  "categories": [
    {
      "kind": "other",
      "name": "Formes de verbes en breton",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Breton",
      "orig": "breton",
      "parents": [],
      "source": "w"
    }
  ],
  "forms": [
    {
      "form": "dastumfet",
      "tags": [
        "unmutated"
      ]
    },
    {
      "form": "tastumfet",
      "tags": [
        "mutation-hard"
      ]
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "verb",
  "pos_title": "Forme de verbe",
  "related": [
    {
      "raw_tags": [
        "Vannetais"
      ],
      "word": "zastumahet"
    }
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Breton trégorrois",
          "orig": "breton trégorrois",
          "parents": [],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "dastumfet"
        }
      ],
      "glosses": [
        "Forme mutée de dastumfet par adoucissement (d > z)."
      ],
      "id": "fr-zastumfet-br-verb-3PwbjYLa",
      "raw_tags": [
        "Trégorrois"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\zas.ˈtỹm.fet\\"
    }
  ],
  "synonyms": [
    {
      "word": "zastumocʼh"
    },
    {
      "word": "zastumot"
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "zastumfet"
}

{
  "categories": [
    "Formes de verbes en breton",
    "breton"
  ],
  "forms": [
    {
      "form": "dastumfet",
      "tags": [
        "unmutated"
      ]
    },
    {
      "form": "tastumfet",
      "tags": [
        "mutation-hard"
      ]
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "verb",
  "pos_title": "Forme de verbe",
  "related": [
    {
      "raw_tags": [
        "Vannetais"
      ],
      "word": "zastumahet"
    }
  ],
  "senses": [
    {
      "categories": [
        "breton trégorrois"
      ],
      "form_of": [
        {
          "word": "dastumfet"
        }
      ],
      "glosses": [
        "Forme mutée de dastumfet par adoucissement (d > z)."
      ],
      "raw_tags": [
        "Trégorrois"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\zas.ˈtỹm.fet\\"
    }
  ],
  "synonyms": [
    {
      "word": "zastumocʼh"
    },
    {
      "word": "zastumot"
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "zastumfet"
}