"ΙΘ΄" meaning in Greek

{
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "numeral"
      },
      "expansion": "ΙΘ΄ • (transliteration needed)",
      "name": "head"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "num",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Greek entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "name": "Greek numeral symbols",
          "parents": [
            "Numeral symbols",
            "Symbols",
            "Letters, symbols, and punctuation",
            "Orthography",
            "Writing",
            "Human behaviour",
            "Language",
            "Human",
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "The Greek number representing the number nineteen or 19."
      ],
      "id": "en-ΙΘ΄-el-num-WQxRnm1O",
      "links": [
        [
          "Greek number",
          "Greek number"
        ],
        [
          "nineteen",
          "nineteen"
        ],
        [
          "19",
          "19"
        ]
      ],
      "synonyms": [
        {
          "word": "ιθ΄"
        }
      ]
    }
  ],
  "word": "ΙΘ΄"
}

{
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "numeral"
      },
      "expansion": "ΙΘ΄ • (transliteration needed)",
      "name": "head"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "num",
  "senses": [
    {
      "categories": [
        "Greek entries with incorrect language header",
        "Greek lemmas",
        "Greek numeral symbols",
        "Greek numerals",
        "Pages with 1 entry",
        "Pages with entries",
        "Requests for transliteration of Greek terms"
      ],
      "glosses": [
        "The Greek number representing the number nineteen or 19."
      ],
      "links": [
        [
          "Greek number",
          "Greek number"
        ],
        [
          "nineteen",
          "nineteen"
        ],
        [
          "19",
          "19"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "word": "ιθ΄"
    }
  ],
  "word": "ΙΘ΄"
}