"εθελοντικά" meaning in Greek

{
  "forms": [
    {
      "form": "ethelontiká",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "adverbs",
        "3": "",
        "4": "",
        "5": "",
        "6": "",
        "head": "",
        "sort": ""
      },
      "expansion": "εθελοντικά • (ethelontiká)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "εθελοντικά • (ethelontiká)",
      "name": "el-adv"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Greek entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "voluntarily (in a voluntary manner)"
      ],
      "id": "en-εθελοντικά-el-adv-zs70rRKu",
      "links": [
        [
          "voluntarily",
          "voluntarily"
        ]
      ],
      "related": [
        {
          "english": "volunteer",
          "roman": "ethelontís",
          "sense": "see",
          "tags": [
            "masculine"
          ],
          "word": "εθελοντής"
        }
      ],
      "synonyms": [
        {
          "roman": "ethelontikós",
          "word": "εθελοντικώς"
        }
      ]
    }
  ],
  "word": "εθελοντικά"
}

{
  "forms": [
    {
      "form": "ethelontiká",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "adverbs",
        "3": "",
        "4": "",
        "5": "",
        "6": "",
        "head": "",
        "sort": ""
      },
      "expansion": "εθελοντικά • (ethelontiká)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "εθελοντικά • (ethelontiká)",
      "name": "el-adv"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "adv",
  "related": [
    {
      "english": "volunteer",
      "roman": "ethelontís",
      "sense": "see",
      "tags": [
        "masculine"
      ],
      "word": "εθελοντής"
    }
  ],
  "senses": [
    {
      "categories": [
        "Greek adverbs",
        "Greek entries with incorrect language header",
        "Greek lemmas"
      ],
      "glosses": [
        "voluntarily (in a voluntary manner)"
      ],
      "links": [
        [
          "voluntarily",
          "voluntarily"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "roman": "ethelontikós",
      "word": "εθελοντικώς"
    }
  ],
  "word": "εθελοντικά"
}