"twenty-firster" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "twenty-first",
        "3": "er"
      },
      "expansion": "twenty-first + -er",
      "name": "suf"
    }
  ],
  "etymology_text": "twenty-first + -er",
  "forms": [
    {
      "form": "twenty-firsters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "twenty-firster (plural twenty-firsters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms suffixed with -er",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1954, Labour Research, volume 43, page 188",
          "text": "On his twenty-firster his father, in a characteristic gesture, had given him an Indian servant, and when Sandys was at the Embassy in Berlin, this splendid creature appeared at his dinner parties in a long white coat, rows of medals […]",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A person's 21st birthday."
      ],
      "id": "en-twenty-firster-en-noun-tiSlDSz2",
      "links": [
        [
          "birthday",
          "birthday"
        ]
      ],
      "raw_glosses": [
        "(informal) A person's 21st birthday."
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "twenty-firster"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "twenty-first",
        "3": "er"
      },
      "expansion": "twenty-first + -er",
      "name": "suf"
    }
  ],
  "etymology_text": "twenty-first + -er",
  "forms": [
    {
      "form": "twenty-firsters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "twenty-firster (plural twenty-firsters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English informal terms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms suffixed with -er",
        "English terms with quotations",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "1954, Labour Research, volume 43, page 188",
          "text": "On his twenty-firster his father, in a characteristic gesture, had given him an Indian servant, and when Sandys was at the Embassy in Berlin, this splendid creature appeared at his dinner parties in a long white coat, rows of medals […]",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A person's 21st birthday."
      ],
      "links": [
        [
          "birthday",
          "birthday"
        ]
      ],
      "raw_glosses": [
        "(informal) A person's 21st birthday."
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "twenty-firster"
}