"zastumor" 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": "dastumor",
      "tags": [
        "unmutated"
      ]
    },
    {
      "form": "tastumor",
      "tags": [
        "mutation-hard"
      ]
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "verb",
  "pos_title": "Forme de verbe",
  "related": [
    {
      "word": "zastumaher"
    }
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "dastumor"
        }
      ],
      "glosses": [
        "Forme mutée de dastumor par adoucissement (d > z)."
      ],
      "id": "fr-zastumor-br-verb-dhf8RWvW"
    }
  ],
  "sounds": [
    {
      "ipa": "\\zasˈtỹmːɔr\\"
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "zastumor"
}

{
  "categories": [
    "Formes de verbes en breton",
    "breton"
  ],
  "forms": [
    {
      "form": "dastumor",
      "tags": [
        "unmutated"
      ]
    },
    {
      "form": "tastumor",
      "tags": [
        "mutation-hard"
      ]
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "verb",
  "pos_title": "Forme de verbe",
  "related": [
    {
      "word": "zastumaher"
    }
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "dastumor"
        }
      ],
      "glosses": [
        "Forme mutée de dastumor par adoucissement (d > z)."
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\zasˈtỹmːɔr\\"
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "zastumor"
}