"᠀" meaning in Mongolian

{
  "head_templates": [
    {
      "args": {
        "1": "mn",
        "2": "punctuation mark"
      },
      "expansion": "᠀ • (∞)",
      "name": "head"
    }
  ],
  "lang": "Mongolian",
  "lang_code": "mn",
  "pos": "punct",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Mongolian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "name": "Mongolian punctuation marks",
          "parents": [
            "Punctuation marks",
            "Letters, symbols, and punctuation",
            "Symbols",
            "Orthography",
            "Writing",
            "Human behaviour",
            "Language",
            "Human",
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Marks start of a book, chapter, passage, or first line"
      ],
      "id": "en-᠀-mn-punct-oTX0LM5H",
      "raw_tags": [
        "punctuation"
      ],
      "synonyms": [
        {
          "alt": "∞",
          "word": "᠀᠋"
        },
        {
          "alt": "∞",
          "word": "᠀᠌"
        },
        {
          "alt": "∞",
          "word": "᠀᠍"
        }
      ]
    }
  ],
  "word": "᠀"
}

{
  "head_templates": [
    {
      "args": {
        "1": "mn",
        "2": "punctuation mark"
      },
      "expansion": "᠀ • (∞)",
      "name": "head"
    }
  ],
  "lang": "Mongolian",
  "lang_code": "mn",
  "pos": "punct",
  "senses": [
    {
      "categories": [
        "Mongolian entries with incorrect language header",
        "Mongolian lemmas",
        "Mongolian punctuation marks"
      ],
      "glosses": [
        "Marks start of a book, chapter, passage, or first line"
      ],
      "raw_tags": [
        "punctuation"
      ]
    }
  ],
  "synonyms": [
    {
      "alt": "∞",
      "word": "᠀᠋"
    },
    {
      "alt": "∞",
      "word": "᠀᠌"
    },
    {
      "alt": "∞",
      "word": "᠀᠍"
    }
  ],
  "word": "᠀"
}

{
  "called_from": "form_descriptions/1698",
  "msg": "unrecognized head form: ∞",
  "path": [
    "᠀"
  ],
  "section": "Mongolian",
  "subsection": "punctuation mark",
  "title": "᠀",
  "trace": ""
}