"◌̀" meaning in Latin

{
  "lang": "Latin",
  "lang_code": "la",
  "pos": "character",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "name": "Latin 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": "Latin entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Latin terms in nonstandard scripts",
          "parents": [
            "Terms in nonstandard scripts",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A diacritical mark of the Latin script, called accentus gravis (“grave accent”) in Latin, and found on à, è, ò."
      ],
      "id": "en-◌̀-la-character-lpp-nhID",
      "links": [
        [
          "diacritical mark",
          "diacritical mark"
        ],
        [
          "Latin script",
          "Latin script"
        ],
        [
          "accentus gravis",
          "accentus gravis#Latin"
        ]
      ],
      "raw_glosses": [
        "(now uncommon) A diacritical mark of the Latin script, called accentus gravis (“grave accent”) in Latin, and found on à, è, ò."
      ],
      "related": [
        {
          "word": "´"
        },
        {
          "word": "^"
        }
      ],
      "tags": [
        "diacritic",
        "uncommon"
      ]
    }
  ],
  "word": "◌̀"
}

{
  "lang": "Latin",
  "lang_code": "la",
  "pos": "character",
  "related": [
    {
      "word": "´"
    },
    {
      "word": "^"
    }
  ],
  "senses": [
    {
      "categories": [
        "Latin diacritical marks",
        "Latin entries with incorrect language header",
        "Latin lemmas",
        "Latin terms in nonstandard scripts",
        "Latin terms with uncommon senses"
      ],
      "glosses": [
        "A diacritical mark of the Latin script, called accentus gravis (“grave accent”) in Latin, and found on à, è, ò."
      ],
      "links": [
        [
          "diacritical mark",
          "diacritical mark"
        ],
        [
          "Latin script",
          "Latin script"
        ],
        [
          "accentus gravis",
          "accentus gravis#Latin"
        ]
      ],
      "raw_glosses": [
        "(now uncommon) A diacritical mark of the Latin script, called accentus gravis (“grave accent”) in Latin, and found on à, è, ò."
      ],
      "tags": [
        "diacritic",
        "uncommon"
      ]
    }
  ],
  "word": "◌̀"
}