"◌̀" meaning in Mandarin

{
  "lang": "Mandarin",
  "lang_code": "cmn",
  "pos": "character",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "name": "Mandarin 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": "Mandarin diacritical marks in Latin script",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Mandarin entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Mandarin terms in nonstandard scripts",
          "parents": [
            "Terms in nonstandard scripts",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Mandarin terms with non-redundant manual script codes",
          "parents": [
            "Terms with non-redundant manual script codes",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Mandarin terms with redundant script codes",
          "parents": [
            "Terms with redundant script codes",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A diacritical mark of the Latin script, called 重音符 (zhòngyīnfú, “grave tone mark”) in Mandarin, and found on À/à, È/è, Ì/ì, Ò/ò, Ù/ù and Ǜ/ǜ, representing the 去聲／去声 (qùshēng, “departing tone”), also known as the 第四聲／第四声 (“fourth tone”), in Pinyin."
      ],
      "id": "en-◌̀-cmn-character-1Yaxd0Mo",
      "links": [
        [
          "diacritical mark",
          "diacritical mark"
        ],
        [
          "重音符",
          "重音符#Mandarin"
        ],
        [
          "À",
          "À#Mandarin"
        ],
        [
          "à",
          "à#Mandarin"
        ],
        [
          "È",
          "È#Mandarin"
        ],
        [
          "è",
          "è#Mandarin"
        ],
        [
          "Ì",
          "Ì#Mandarin"
        ],
        [
          "ì",
          "ì#Mandarin"
        ],
        [
          "Ò",
          "Ò#Mandarin"
        ],
        [
          "ò",
          "ò#Mandarin"
        ],
        [
          "Ù",
          "Ù#Mandarin"
        ],
        [
          "ù",
          "ù#Mandarin"
        ],
        [
          "Ǜ",
          "Ǜ#Mandarin"
        ],
        [
          "ǜ",
          "ǜ#Mandarin"
        ],
        [
          "去聲",
          "去聲#Chinese"
        ],
        [
          "去声",
          "去声#Chinese"
        ],
        [
          "第四聲",
          "第四聲#Chinese"
        ],
        [
          "第四声",
          "第四声#Chinese"
        ],
        [
          "Pinyin",
          "Pinyin"
        ]
      ],
      "related": [
        {
          "english": "first tone",
          "word": "◌̄"
        },
        {
          "english": "second tone",
          "word": "◌́"
        },
        {
          "english": "third tone",
          "word": "◌̌"
        },
        {
          "english": "fifth tone",
          "word": "ꞏ◌"
        }
      ],
      "tags": [
        "diacritic"
      ]
    }
  ],
  "word": "◌̀"
}

{
  "lang": "Mandarin",
  "lang_code": "cmn",
  "pos": "character",
  "related": [
    {
      "english": "first tone",
      "word": "◌̄"
    },
    {
      "english": "second tone",
      "word": "◌́"
    },
    {
      "english": "third tone",
      "word": "◌̌"
    },
    {
      "english": "fifth tone",
      "word": "ꞏ◌"
    }
  ],
  "senses": [
    {
      "categories": [
        "Mandarin diacritical marks",
        "Mandarin diacritical marks in Latin script",
        "Mandarin entries with incorrect language header",
        "Mandarin lemmas",
        "Mandarin terms in nonstandard scripts",
        "Mandarin terms with non-redundant manual script codes",
        "Mandarin terms with redundant script codes"
      ],
      "glosses": [
        "A diacritical mark of the Latin script, called 重音符 (zhòngyīnfú, “grave tone mark”) in Mandarin, and found on À/à, È/è, Ì/ì, Ò/ò, Ù/ù and Ǜ/ǜ, representing the 去聲／去声 (qùshēng, “departing tone”), also known as the 第四聲／第四声 (“fourth tone”), in Pinyin."
      ],
      "links": [
        [
          "diacritical mark",
          "diacritical mark"
        ],
        [
          "重音符",
          "重音符#Mandarin"
        ],
        [
          "À",
          "À#Mandarin"
        ],
        [
          "à",
          "à#Mandarin"
        ],
        [
          "È",
          "È#Mandarin"
        ],
        [
          "è",
          "è#Mandarin"
        ],
        [
          "Ì",
          "Ì#Mandarin"
        ],
        [
          "ì",
          "ì#Mandarin"
        ],
        [
          "Ò",
          "Ò#Mandarin"
        ],
        [
          "ò",
          "ò#Mandarin"
        ],
        [
          "Ù",
          "Ù#Mandarin"
        ],
        [
          "ù",
          "ù#Mandarin"
        ],
        [
          "Ǜ",
          "Ǜ#Mandarin"
        ],
        [
          "ǜ",
          "ǜ#Mandarin"
        ],
        [
          "去聲",
          "去聲#Chinese"
        ],
        [
          "去声",
          "去声#Chinese"
        ],
        [
          "第四聲",
          "第四聲#Chinese"
        ],
        [
          "第四声",
          "第四声#Chinese"
        ],
        [
          "Pinyin",
          "Pinyin"
        ]
      ],
      "tags": [
        "diacritic"
      ]
    }
  ],
  "word": "◌̀"
}