"solemniis" meaning in Latin

{
  "forms": [
    {
      "form": "sōlemniīs",
      "tags": [
        "canonical"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "la",
        "2": "noun form",
        "head": "sōlemniīs"
      },
      "expansion": "sōlemniīs",
      "name": "head"
    }
  ],
  "lang": "Latin",
  "lang_code": "la",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Latin entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "sōlemnium"
        }
      ],
      "glosses": [
        "dative/ablative plural of sōlemnium"
      ],
      "id": "en-solemniis-la-noun-GmrMNcC4",
      "links": [
        [
          "sōlemnium",
          "solemnium#Latin"
        ]
      ],
      "tags": [
        "ablative",
        "dative",
        "form-of",
        "plural"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[soːˈɫɛm.ni.iːs]",
      "tags": [
        "Classical-Latin"
      ]
    },
    {
      "ipa": "[soˈlɛm.ni.is]",
      "note": "modern Italianate Ecclesiastical"
    }
  ],
  "word": "solemniis"
}

{
  "forms": [
    {
      "form": "sōlemniīs",
      "tags": [
        "canonical"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "la",
        "2": "noun form",
        "head": "sōlemniīs"
      },
      "expansion": "sōlemniīs",
      "name": "head"
    }
  ],
  "lang": "Latin",
  "lang_code": "la",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Latin 4-syllable words",
        "Latin entries with incorrect language header",
        "Latin non-lemma forms",
        "Latin noun forms",
        "Latin terms with IPA pronunciation",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "form_of": [
        {
          "word": "sōlemnium"
        }
      ],
      "glosses": [
        "dative/ablative plural of sōlemnium"
      ],
      "links": [
        [
          "sōlemnium",
          "solemnium#Latin"
        ]
      ],
      "tags": [
        "ablative",
        "dative",
        "form-of",
        "plural"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[soːˈɫɛm.ni.iːs]",
      "tags": [
        "Classical-Latin"
      ]
    },
    {
      "ipa": "[soˈlɛm.ni.is]",
      "note": "modern Italianate Ecclesiastical"
    }
  ],
  "word": "solemniis"
}