"-ьнъ" meaning in Vieux slave

{
  "categories": [
    {
      "kind": "other",
      "name": "Mots en vieux slave issus d’un mot en proto-slave",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Suffixes en vieux slave",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Vieux slave",
      "orig": "vieux slave",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Étymologies en vieux slave incluant une reconstruction",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "Du proto-slave *-ьnъ (en). Ce suffixe adjectival est le plus fréquent en vieux slave. Il a des variantes qui sont -нъ (dans сланъ), -єнъ (dans стѹдєнъ), -ѣнъ, -анъ et -инъ (dans змиинъ) ^([1]). Probablement le même suffixe que -inus en latin."
  ],
  "lang": "Vieux slave",
  "lang_code": "cu",
  "pos": "suffix",
  "pos_title": "Suffixe",
  "raw_tags": [
    "-ĭnŭ"
  ],
  "related": [
    {
      "word": "-ьнь"
    }
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Wiktionnaire:Exemples manquants en vieux slave",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Suffixe adjectival."
      ],
      "id": "fr--ьнъ-cu-suffix-wry7GbZj"
    }
  ],
  "tags": [
    "morpheme"
  ],
  "word": "-ьнъ"
}

{
  "categories": [
    "Mots en vieux slave issus d’un mot en proto-slave",
    "Suffixes en vieux slave",
    "vieux slave",
    "Étymologies en vieux slave incluant une reconstruction"
  ],
  "etymology_texts": [
    "Du proto-slave *-ьnъ (en). Ce suffixe adjectival est le plus fréquent en vieux slave. Il a des variantes qui sont -нъ (dans сланъ), -єнъ (dans стѹдєнъ), -ѣнъ, -анъ et -инъ (dans змиинъ) ^([1]). Probablement le même suffixe que -inus en latin."
  ],
  "lang": "Vieux slave",
  "lang_code": "cu",
  "pos": "suffix",
  "pos_title": "Suffixe",
  "raw_tags": [
    "-ĭnŭ"
  ],
  "related": [
    {
      "word": "-ьнь"
    }
  ],
  "senses": [
    {
      "categories": [
        "Wiktionnaire:Exemples manquants en vieux slave"
      ],
      "glosses": [
        "Suffixe adjectival."
      ]
    }
  ],
  "tags": [
    "morpheme"
  ],
  "word": "-ьнъ"
}