"каинъ" meaning in Vieux slave

{
  "categories": [
    {
      "kind": "other",
      "name": "Noms propres en vieux slave",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Vieux slave",
      "orig": "vieux slave",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Vieux slave",
  "lang_code": "cu",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en vieux slave de la religion",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Caïn."
      ],
      "id": "fr-каинъ-cu-name-5Wata6p7",
      "topics": [
        "religion"
      ]
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "каинъ"
}

{
  "categories": [
    "Noms propres en vieux slave",
    "vieux slave"
  ],
  "lang": "Vieux slave",
  "lang_code": "cu",
  "pos": "name",
  "pos_title": "Nom propre",
  "senses": [
    {
      "categories": [
        "Lexique en vieux slave de la religion"
      ],
      "glosses": [
        "Caïn."
      ],
      "topics": [
        "religion"
      ]
    }
  ],
  "tags": [
    "masculine"
  ],
  "word": "каинъ"
}