"arco da vella" meaning in Galician

{
  "etymology_text": "Probably mythological. Its literal meaning is \"old woman's bow\".",
  "forms": [
    {
      "form": "arcos da vella",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "arco da vella m (plural arcos da vella)",
      "name": "gl-noun"
    }
  ],
  "lang": "Galician",
  "lang_code": "gl",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Galician entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "gl",
          "name": "Light",
          "orig": "gl:Light",
          "parents": [
            "Energy",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "rainbow"
      ],
      "id": "en-arco_da_vella-gl-noun-j87QC2zi",
      "links": [
        [
          "rainbow",
          "rainbow"
        ]
      ],
      "synonyms": [
        {
          "word": "arco das vellas"
        },
        {
          "word": "arco de vellas"
        }
      ],
      "tags": [
        "masculine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈaɾkʊ ða‿ˈβɛʎɐ]"
    }
  ],
  "word": "arco da vella"
}

{
  "etymology_text": "Probably mythological. Its literal meaning is \"old woman's bow\".",
  "forms": [
    {
      "form": "arcos da vella",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "arco da vella m (plural arcos da vella)",
      "name": "gl-noun"
    }
  ],
  "lang": "Galician",
  "lang_code": "gl",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Galician countable nouns",
        "Galician entries with incorrect language header",
        "Galician lemmas",
        "Galician masculine nouns",
        "Galician multiword terms",
        "Galician nouns",
        "Galician terms with IPA pronunciation",
        "gl:Light"
      ],
      "glosses": [
        "rainbow"
      ],
      "links": [
        [
          "rainbow",
          "rainbow"
        ]
      ],
      "tags": [
        "masculine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈaɾkʊ ða‿ˈβɛʎɐ]"
    }
  ],
  "synonyms": [
    {
      "word": "arco das vellas"
    },
    {
      "word": "arco de vellas"
    }
  ],
  "word": "arco da vella"
}