"gaviota sombría" meaning in Spanish

{
  "forms": [
    {
      "form": "gaviotas sombrías",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "gaviota sombría f (plural gaviotas sombrías)",
      "name": "es-noun"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "lifeform",
          "langcode": "es",
          "name": "Gulls",
          "orig": "es:Gulls",
          "parents": [
            "Seabirds",
            "Birds",
            "Vertebrates",
            "Chordates",
            "Animals",
            "Lifeforms",
            "All topics",
            "Life",
            "Fundamental",
            "Nature"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The lesser black-backed gull."
      ],
      "id": "en-gaviota_sombría-es-noun-F1ZDBxZb",
      "links": [
        [
          "lesser black-backed gull",
          "lesser black-backed gull"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "word": "gaviota sombría"
}

{
  "forms": [
    {
      "form": "gaviotas sombrías",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "gaviota sombría f (plural gaviotas sombrías)",
      "name": "es-noun"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Pages with 1 entry",
        "Pages with entries",
        "Spanish countable nouns",
        "Spanish entries with incorrect language header",
        "Spanish feminine nouns",
        "Spanish lemmas",
        "Spanish multiword terms",
        "Spanish nouns",
        "Spanish nouns with red links in their headword lines",
        "es:Gulls"
      ],
      "glosses": [
        "The lesser black-backed gull."
      ],
      "links": [
        [
          "lesser black-backed gull",
          "lesser black-backed gull"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "word": "gaviota sombría"
}