"праотьць" meaning in Vieux slave

{
  "categories": [
    {
      "kind": "other",
      "name": "Noms communs en vieux slave",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Vieux slave",
      "orig": "vieux slave",
      "parents": [],
      "source": "w"
    }
  ],
  "derived": [
    {
      "lang": "Tchèque",
      "lang_code": "cs",
      "word": "praotec"
    }
  ],
  "etymology_texts": [
    "Mot composé de пра- et отьць."
  ],
  "lang": "Vieux slave",
  "lang_code": "cu",
  "pos": "noun",
  "pos_title": "Nom commun",
  "related": [
    {
      "word": "прѣотьць"
    }
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en vieux slave de la famille",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Arrière-grand-père, aïeul."
      ],
      "id": "fr-праотьць-cu-noun-5hORjrJx",
      "raw_tags": [
        "Famille"
      ]
    },
    {
      "glosses": [
        "Ancêtre."
      ],
      "id": "fr-праотьць-cu-noun-w4x978PC"
    }
  ],
  "synonyms": [
    {
      "word": "прародитєль"
    },
    {
      "word": "прѣродитєль"
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "праотьць"
}

{
  "categories": [
    "Noms communs en vieux slave",
    "vieux slave"
  ],
  "derived": [
    {
      "lang": "Tchèque",
      "lang_code": "cs",
      "word": "praotec"
    }
  ],
  "etymology_texts": [
    "Mot composé de пра- et отьць."
  ],
  "lang": "Vieux slave",
  "lang_code": "cu",
  "pos": "noun",
  "pos_title": "Nom commun",
  "related": [
    {
      "word": "прѣотьць"
    }
  ],
  "senses": [
    {
      "categories": [
        "Lexique en vieux slave de la famille"
      ],
      "glosses": [
        "Arrière-grand-père, aïeul."
      ],
      "raw_tags": [
        "Famille"
      ]
    },
    {
      "glosses": [
        "Ancêtre."
      ]
    }
  ],
  "synonyms": [
    {
      "word": "прародитєль"
    },
    {
      "word": "прѣродитєль"
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "праотьць"
}