"ero" meaning in Breton

{
  "categories": [
    {
      "kind": "other",
      "name": "Mots parfois masculins ou féminins en breton",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Noms communs en breton",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Breton",
      "orig": "breton",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "erv"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Variantes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Variantes en breton",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Variante de erv (« sillon »)."
      ],
      "id": "fr-ero-br-noun-GBpumIWN",
      "tags": [
        "alt-of"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈeː.ro\\"
    }
  ],
  "tags": [
    "feminine",
    "masculine"
  ],
  "word": "ero"
}

{
  "categories": [
    "Mots parfois masculins ou féminins en breton",
    "Noms communs en breton",
    "breton"
  ],
  "lang": "Breton",
  "lang_code": "br",
  "pos": "noun",
  "pos_title": "Nom commun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "erv"
        }
      ],
      "categories": [
        "Variantes",
        "Variantes en breton"
      ],
      "glosses": [
        "Variante de erv (« sillon »)."
      ],
      "tags": [
        "alt-of"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈeː.ro\\"
    }
  ],
  "tags": [
    "feminine",
    "masculine"
  ],
  "word": "ero"
}