"tšau" meaning in Estonian

{
  "head_templates": [
    {
      "args": {
        "1": "et",
        "2": "interjection"
      },
      "expansion": "tšau",
      "name": "head"
    }
  ],
  "lang": "Estonian",
  "lang_code": "et",
  "pos": "intj",
  "senses": [
    {
      "alt_of": [
        {
          "word": "tsau"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Estonian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Alternative form of tsau."
      ],
      "id": "en-tšau-et-intj-TvCKF3ut",
      "links": [
        [
          "tsau",
          "tsau#Estonian"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "tšau"
}

{
  "head_templates": [
    {
      "args": {
        "1": "et",
        "2": "interjection"
      },
      "expansion": "tšau",
      "name": "head"
    }
  ],
  "lang": "Estonian",
  "lang_code": "et",
  "pos": "intj",
  "senses": [
    {
      "alt_of": [
        {
          "word": "tsau"
        }
      ],
      "categories": [
        "Estonian entries with incorrect language header",
        "Estonian interjections",
        "Estonian lemmas",
        "Estonian terms spelled with Š",
        "Estonian terms spelled with ◌̌"
      ],
      "glosses": [
        "Alternative form of tsau."
      ],
      "links": [
        [
          "tsau",
          "tsau#Estonian"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "tšau"
}