"Da" meaning in Translingual

{
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "symbol"
      },
      "expansion": "Da",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "symbol",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "the atomic mass unit",
          "word": "the dalton"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Translingual entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "mul",
          "name": "Metrology",
          "orig": "mul:Metrology",
          "parents": [
            "Applied sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Symbol for the dalton, the atomic mass unit."
      ],
      "id": "en-Da-mul-symbol-kPnuoEiK",
      "links": [
        [
          "metrology",
          "metrology"
        ],
        [
          "dalton",
          "dalton#English"
        ],
        [
          "atomic mass unit",
          "atomic mass unit"
        ]
      ],
      "raw_glosses": [
        "(metrology) Symbol for the dalton, the atomic mass unit."
      ],
      "tags": [
        "alt-of",
        "symbol"
      ],
      "topics": [
        "metrology"
      ]
    }
  ],
  "word": "Da"
}

{
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "symbol"
      },
      "expansion": "Da",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "symbol",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "the atomic mass unit",
          "word": "the dalton"
        }
      ],
      "categories": [
        "Translingual entries with incorrect language header",
        "Translingual lemmas",
        "Translingual symbols",
        "mul:Metrology"
      ],
      "glosses": [
        "Symbol for the dalton, the atomic mass unit."
      ],
      "links": [
        [
          "metrology",
          "metrology"
        ],
        [
          "dalton",
          "dalton#English"
        ],
        [
          "atomic mass unit",
          "atomic mass unit"
        ]
      ],
      "raw_glosses": [
        "(metrology) Symbol for the dalton, the atomic mass unit."
      ],
      "tags": [
        "alt-of",
        "symbol"
      ],
      "topics": [
        "metrology"
      ]
    }
  ],
  "word": "Da"
}