"Mv" meaning in Translingual

{
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "symbol"
      },
      "expansion": "Mv",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "symbol",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "name": "Symbols for chemical elements",
          "parents": [
            "Chemical elements",
            "Matter",
            "Chemistry",
            "Nature",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Translingual entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "former symbol for mendelevium; now Md"
      ],
      "id": "en-Mv-mul-symbol-ZQtQh1X9",
      "links": [
        [
          "mendelevium",
          "mendelevium"
        ],
        [
          "Md",
          "Md"
        ]
      ]
    }
  ],
  "word": "Mv"
}

{
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "symbol"
      },
      "expansion": "Mv",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "symbol",
  "senses": [
    {
      "categories": [
        "Symbols for chemical elements",
        "Translingual entries with incorrect language header",
        "Translingual lemmas",
        "Translingual symbols"
      ],
      "glosses": [
        "former symbol for mendelevium; now Md"
      ],
      "links": [
        [
          "mendelevium",
          "mendelevium"
        ],
        [
          "Md",
          "Md"
        ]
      ]
    }
  ],
  "word": "Mv"
}