"゜" meaning in Japanese

{
  "head_templates": [
    {
      "args": {
        "1": "ja",
        "2": "diacritical mark"
      },
      "expansion": "゜",
      "name": "head"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "character",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "name": "Japanese 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": "Japanese entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The handakuten, which indicates that a kana with an initial of h- should be pronounced with p- (i.e. ha with a handakuten is pronounced as pa). It is also sometimes used with k- kana to indicate ng- (a phoneme that is usually an allophone of /g/)."
      ],
      "id": "en-゜-ja-character-~izW3u0Y",
      "links": [
        [
          "handakuten",
          "handakuten"
        ],
        [
          "phoneme",
          "phoneme"
        ],
        [
          "allophone",
          "allophone"
        ]
      ],
      "related": [
        {
          "word": "゛: the dakuten"
        },
        {
          "roman": "maru",
          "tags": [
            "colloquial"
          ],
          "word": "まる: the handakuten mark"
        }
      ],
      "tags": [
        "diacritic"
      ]
    }
  ],
  "word": "゜"
}

{
  "head_templates": [
    {
      "args": {
        "1": "ja",
        "2": "diacritical mark"
      },
      "expansion": "゜",
      "name": "head"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "character",
  "related": [
    {
      "word": "゛: the dakuten"
    },
    {
      "roman": "maru",
      "tags": [
        "colloquial"
      ],
      "word": "まる: the handakuten mark"
    }
  ],
  "senses": [
    {
      "categories": [
        "Japanese diacritical marks",
        "Japanese entries with incorrect language header",
        "Japanese lemmas"
      ],
      "glosses": [
        "The handakuten, which indicates that a kana with an initial of h- should be pronounced with p- (i.e. ha with a handakuten is pronounced as pa). It is also sometimes used with k- kana to indicate ng- (a phoneme that is usually an allophone of /g/)."
      ],
      "links": [
        [
          "handakuten",
          "handakuten"
        ],
        [
          "phoneme",
          "phoneme"
        ],
        [
          "allophone",
          "allophone"
        ]
      ],
      "tags": [
        "diacritic"
      ]
    }
  ],
  "word": "゜"
}