"-∅" meaning in Kalmyk

{
  "etymology_number": 1,
  "etymology_text": "From the fact that no true third person pronoun existed, so it was not put word-finally like other personal markers such as -в (-v), -ч (-ç), etc.",
  "head_templates": [
    {
      "args": {
        "1": "xal",
        "2": "suffix"
      },
      "expansion": "-∅",
      "name": "head"
    }
  ],
  "lang": "Kalmyk",
  "lang_code": "xal",
  "pos": "suffix",
  "senses": [
    {
      "glosses": [
        "Used as a third-person copula, meaning ‘He/she/it/they is/are …’"
      ],
      "id": "en--∅-xal-suffix-bP1EeHM3",
      "links": [
        [
          "He",
          "He#English"
        ],
        [
          "she",
          "she#English"
        ],
        [
          "it",
          "it#English"
        ],
        [
          "they",
          "they#English"
        ],
        [
          "is",
          "is#English"
        ],
        [
          "are",
          "are#English"
        ]
      ],
      "raw_glosses": [
        "(predicative) Used as a third-person copula, meaning ‘He/she/it/they is/are …’"
      ],
      "synonyms": [
        {
          "word": "болх"
        }
      ],
      "tags": [
        "morpheme",
        "predicative"
      ]
    },
    {
      "categories": [],
      "examples": [
        {
          "english": "He/she/it says",
          "roman": "En kelnä",
          "text": "Эн келнә",
          "type": "example"
        }
      ],
      "glosses": [
        "A third-person singular verbal suffix."
      ],
      "id": "en--∅-xal-suffix-nXOZVfia",
      "raw_glosses": [
        "(predicative) A third-person singular verbal suffix."
      ],
      "tags": [
        "morpheme",
        "predicative"
      ]
    }
  ],
  "word": "-∅"
}

{
  "etymology_number": 2,
  "etymology_text": "Root form of the verb (without the -х (-x) suffix in the dictionary form).",
  "head_templates": [
    {
      "args": {
        "1": "xal",
        "2": "suffix"
      },
      "expansion": "-∅",
      "name": "head"
    }
  ],
  "lang": "Kalmyk",
  "lang_code": "xal",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        {
          "_dis": "11 28 61",
          "kind": "other",
          "name": "Kalmyk entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        },
        {
          "_dis": "16 27 57",
          "kind": "other",
          "name": "Kalmyk terms in nonstandard scripts",
          "parents": [
            "Terms in nonstandard scripts",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "examples": [
        {
          "english": "Speak!",
          "roman": "Kel!",
          "text": "Кел!",
          "type": "example"
        }
      ],
      "glosses": [
        "Indicates the imperative."
      ],
      "id": "en--∅-xal-suffix-8G~qvqJi",
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ə/"
    }
  ],
  "word": "-∅"
}

{
  "categories": [
    "Kalmyk entries with incorrect language header",
    "Kalmyk lemmas",
    "Kalmyk suffixes",
    "Kalmyk terms in nonstandard scripts",
    "Pages with 10 entries",
    "Pages with entries"
  ],
  "etymology_number": 1,
  "etymology_text": "From the fact that no true third person pronoun existed, so it was not put word-finally like other personal markers such as -в (-v), -ч (-ç), etc.",
  "head_templates": [
    {
      "args": {
        "1": "xal",
        "2": "suffix"
      },
      "expansion": "-∅",
      "name": "head"
    }
  ],
  "lang": "Kalmyk",
  "lang_code": "xal",
  "pos": "suffix",
  "senses": [
    {
      "glosses": [
        "Used as a third-person copula, meaning ‘He/she/it/they is/are …’"
      ],
      "links": [
        [
          "He",
          "He#English"
        ],
        [
          "she",
          "she#English"
        ],
        [
          "it",
          "it#English"
        ],
        [
          "they",
          "they#English"
        ],
        [
          "is",
          "is#English"
        ],
        [
          "are",
          "are#English"
        ]
      ],
      "raw_glosses": [
        "(predicative) Used as a third-person copula, meaning ‘He/she/it/they is/are …’"
      ],
      "synonyms": [
        {
          "word": "болх"
        }
      ],
      "tags": [
        "morpheme",
        "predicative"
      ]
    },
    {
      "categories": [
        "Kalmyk terms with usage examples"
      ],
      "examples": [
        {
          "english": "He/she/it says",
          "roman": "En kelnä",
          "text": "Эн келнә",
          "type": "example"
        }
      ],
      "glosses": [
        "A third-person singular verbal suffix."
      ],
      "raw_glosses": [
        "(predicative) A third-person singular verbal suffix."
      ],
      "tags": [
        "morpheme",
        "predicative"
      ]
    }
  ],
  "word": "-∅"
}

{
  "categories": [
    "Kalmyk entries with incorrect language header",
    "Kalmyk lemmas",
    "Kalmyk suffixes",
    "Kalmyk terms in nonstandard scripts",
    "Pages with 10 entries",
    "Pages with entries"
  ],
  "etymology_number": 2,
  "etymology_text": "Root form of the verb (without the -х (-x) suffix in the dictionary form).",
  "head_templates": [
    {
      "args": {
        "1": "xal",
        "2": "suffix"
      },
      "expansion": "-∅",
      "name": "head"
    }
  ],
  "lang": "Kalmyk",
  "lang_code": "xal",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        "Kalmyk terms with usage examples"
      ],
      "examples": [
        {
          "english": "Speak!",
          "roman": "Kel!",
          "text": "Кел!",
          "type": "example"
        }
      ],
      "glosses": [
        "Indicates the imperative."
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ə/"
    }
  ],
  "word": "-∅"
}