"я̈" meaning in Russian

{
  "forms": [
    {
      "form": "jǫ",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "Я̈",
      "tags": [
        "uppercase"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "ru",
        "2": "letter",
        "3": "lower case",
        "4": "",
        "5": "upper case",
        "6": "Я̈"
      },
      "expansion": "я̈ • (jǫ) (lower case, upper case Я̈)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "я̈ • (jǫ) (lower case, upper case Я̈)",
      "name": "ru-letter"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "character",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Russian entries with incorrect language header",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "The letter я with a diaeresis."
      ],
      "id": "en-я̈-ru-character-0UQc4oK7",
      "links": [
        [
          "я",
          "я"
        ]
      ],
      "qualifier": "pre-1918 spelling",
      "raw_glosses": [
        "(obsolete, pre-1918 spelling) The letter я with a diaeresis."
      ],
      "tags": [
        "letter",
        "lowercase",
        "obsolete"
      ]
    }
  ],
  "word": "я̈"
}

{
  "forms": [
    {
      "form": "jǫ",
      "tags": [
        "romanization"
      ]
    },
    {
      "form": "Я̈",
      "tags": [
        "uppercase"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "ru",
        "2": "letter",
        "3": "lower case",
        "4": "",
        "5": "upper case",
        "6": "Я̈"
      },
      "expansion": "я̈ • (jǫ) (lower case, upper case Я̈)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "я̈ • (jǫ) (lower case, upper case Я̈)",
      "name": "ru-letter"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "character",
  "senses": [
    {
      "categories": [
        "Pages with 1 entry",
        "Pages with entries",
        "Russian entries with incorrect language header",
        "Russian lemmas",
        "Russian letters",
        "Russian terms spelled with Я̈",
        "Russian terms with obsolete senses"
      ],
      "glosses": [
        "The letter я with a diaeresis."
      ],
      "links": [
        [
          "я",
          "я"
        ]
      ],
      "qualifier": "pre-1918 spelling",
      "raw_glosses": [
        "(obsolete, pre-1918 spelling) The letter я with a diaeresis."
      ],
      "tags": [
        "letter",
        "lowercase",
        "obsolete"
      ]
    }
  ],
  "word": "я̈"
}