"MDCCLXVI" meaning in Universeel taalgebruik

{
  "categories": [
    {
      "kind": "other",
      "name": "Hoofdtelwoord in het universeel taalgebruik",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Woorden in het universeel taalgebruik",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Universeel taalgebruik",
  "lang_code": "unknown",
  "pos": "num",
  "pos_title": "Hoofdtelwoord",
  "senses": [
    {
      "id": "nl-MDCCLXVI-unknown-num-47DEQpj8",
      "tags": [
        "no-gloss"
      ]
    }
  ],
  "word": "MDCCLXVI"
}

{
  "categories": [
    "Hoofdtelwoord in het universeel taalgebruik",
    "Woorden in het universeel taalgebruik"
  ],
  "lang": "Universeel taalgebruik",
  "lang_code": "unknown",
  "pos": "num",
  "pos_title": "Hoofdtelwoord",
  "senses": [
    {
      "tags": [
        "no-gloss"
      ]
    }
  ],
  "word": "MDCCLXVI"
}