"mataviejos" meaning in Spanish

{
  "etymology_templates": [
    {
      "args": {
        "1": "matar<t:to kill>",
        "2": "viejo<t:old people><pl:1>"
      },
      "expansion": "Verb-object compound, composed of mata (“to kill”) + viejos (“old people”)",
      "name": "es-verb-obj"
    }
  ],
  "etymology_text": "Verb-object compound, composed of mata (“to kill”) + viejos (“old people”).",
  "forms": [
    {
      "form": "mataviejos",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "mataviejos m (plural mataviejos)",
      "name": "es-noun"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish links with redundant wikilinks",
          "parents": [
            "Links with redundant wikilinks",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish verb-object compounds",
          "parents": [
            "Verb-object compounds",
            "Compound terms",
            "Terms by etymology"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "old-person killer"
      ],
      "id": "en-mataviejos-es-noun-7lmXWSF~",
      "tags": [
        "masculine"
      ]
    }
  ],
  "word": "mataviejos"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "matar<t:to kill>",
        "2": "viejo<t:old people><pl:1>"
      },
      "expansion": "Verb-object compound, composed of mata (“to kill”) + viejos (“old people”)",
      "name": "es-verb-obj"
    }
  ],
  "etymology_text": "Verb-object compound, composed of mata (“to kill”) + viejos (“old people”).",
  "forms": [
    {
      "form": "mataviejos",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "mataviejos m (plural mataviejos)",
      "name": "es-noun"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Spanish countable nouns",
        "Spanish entries with incorrect language header",
        "Spanish lemmas",
        "Spanish links with redundant wikilinks",
        "Spanish masculine nouns",
        "Spanish nouns",
        "Spanish verb-object compounds"
      ],
      "glosses": [
        "old-person killer"
      ],
      "tags": [
        "masculine"
      ]
    }
  ],
  "word": "mataviejos"
}