"◌̃" meaning in Middle English

{
  "descendants": [
    {
      "depth": 1,
      "templates": [
        {
          "args": {
            "1": "en",
            "2": "◌̃"
          },
          "expansion": "English: ◌̃",
          "name": "desc"
        }
      ],
      "text": "English: ◌̃"
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "enm",
        "2": "diacritical mark"
      },
      "expansion": "◌̃",
      "name": "head"
    }
  ],
  "lang": "Middle English",
  "lang_code": "enm",
  "pos": "character",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "name": "Middle English diacritical marks",
          "parents": [
            "Diacritical marks",
            "Letters, symbols, and punctuation",
            "Symbols",
            "Orthography",
            "Writing",
            "Human behaviour",
            "Language",
            "Human",
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Middle English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Middle English terms in nonstandard scripts",
          "parents": [
            "Terms in nonstandard scripts",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Written on a letter, usually a vowel, in place of an omitted n or m."
      ],
      "id": "en-◌̃-enm-character-K3-c53rH",
      "tags": [
        "diacritic"
      ]
    }
  ],
  "word": "◌̃"
}

{
  "descendants": [
    {
      "depth": 1,
      "templates": [
        {
          "args": {
            "1": "en",
            "2": "◌̃"
          },
          "expansion": "English: ◌̃",
          "name": "desc"
        }
      ],
      "text": "English: ◌̃"
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "enm",
        "2": "diacritical mark"
      },
      "expansion": "◌̃",
      "name": "head"
    }
  ],
  "lang": "Middle English",
  "lang_code": "enm",
  "pos": "character",
  "senses": [
    {
      "categories": [
        "Middle English diacritical marks",
        "Middle English entries with incorrect language header",
        "Middle English lemmas",
        "Middle English terms in nonstandard scripts"
      ],
      "glosses": [
        "Written on a letter, usually a vowel, in place of an omitted n or m."
      ],
      "tags": [
        "diacritic"
      ]
    }
  ],
  "word": "◌̃"
}