"ferr" meaning in Cornish

{
  "head_templates": [
    {
      "args": {
        "1": "kw",
        "2": "mutated adjective"
      },
      "expansion": "ferr",
      "name": "head"
    }
  ],
  "lang": "Cornish",
  "lang_code": "kw",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Cornish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 4 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "berr"
        }
      ],
      "glosses": [
        "Mixed mutation of berr."
      ],
      "id": "en-ferr-kw-adj-WBsaql1j",
      "links": [
        [
          "berr",
          "berr#Cornish"
        ]
      ],
      "tags": [
        "form-of",
        "mutation-mixed"
      ]
    }
  ],
  "word": "ferr"
}

{
  "head_templates": [
    {
      "args": {
        "1": "kw",
        "2": "mutated adjective"
      },
      "expansion": "ferr",
      "name": "head"
    }
  ],
  "lang": "Cornish",
  "lang_code": "kw",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "Cornish entries with incorrect language header",
        "Cornish mixed-mutation forms",
        "Cornish mutated adjectives",
        "Cornish non-lemma forms",
        "Pages with 4 entries",
        "Pages with entries"
      ],
      "form_of": [
        {
          "word": "berr"
        }
      ],
      "glosses": [
        "Mixed mutation of berr."
      ],
      "links": [
        [
          "berr",
          "berr#Cornish"
        ]
      ],
      "tags": [
        "form-of",
        "mutation-mixed"
      ]
    }
  ],
  "word": "ferr"
}