"atavismo" meaning in Spanish

{
  "forms": [
    {
      "form": "atavismos",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "atavismo m (plural atavismos)",
      "name": "es-noun"
    }
  ],
  "hyphenation": [
    "a‧ta‧vis‧mo"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 4 entries",
          "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"
        }
      ],
      "glosses": [
        "atavism"
      ],
      "id": "en-atavismo-es-noun-Tf1htJor",
      "links": [
        [
          "atavism",
          "atavism"
        ]
      ],
      "related": [
        {
          "word": "atávico"
        }
      ],
      "tags": [
        "masculine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ataˈbismo/"
    },
    {
      "ipa": "[a.t̪aˈβ̞iz.mo]"
    },
    {
      "rhymes": "-ismo"
    }
  ],
  "word": "atavismo"
}

{
  "forms": [
    {
      "form": "atavismos",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "atavismo m (plural atavismos)",
      "name": "es-noun"
    }
  ],
  "hyphenation": [
    "a‧ta‧vis‧mo"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "related": [
    {
      "word": "atávico"
    }
  ],
  "senses": [
    {
      "categories": [
        "Pages with 4 entries",
        "Pages with entries",
        "Rhymes:Spanish/ismo",
        "Rhymes:Spanish/ismo/4 syllables",
        "Spanish 4-syllable words",
        "Spanish countable nouns",
        "Spanish entries with incorrect language header",
        "Spanish lemmas",
        "Spanish masculine nouns",
        "Spanish nouns",
        "Spanish terms with IPA pronunciation"
      ],
      "glosses": [
        "atavism"
      ],
      "links": [
        [
          "atavism",
          "atavism"
        ]
      ],
      "tags": [
        "masculine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ataˈbismo/"
    },
    {
      "ipa": "[a.t̪aˈβ̞iz.mo]"
    },
    {
      "rhymes": "-ismo"
    }
  ],
  "word": "atavismo"
}