"..--.." meaning in Translingual

{
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "punct",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "question mark",
          "word": "?"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Translingual entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "name": "Translingual punctuation marks",
          "parents": [
            "Punctuation marks",
            "Letters, symbols, and punctuation",
            "Symbols",
            "Orthography",
            "Writing",
            "Human behaviour",
            "Language",
            "Human",
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Translingual terms with non-redundant manual script codes",
          "parents": [
            "Terms with non-redundant manual script codes",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Translingual terms with redundant sortkeys",
          "parents": [
            "Terms with redundant sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Visual rendering of Morse code for ? (“question mark”)."
      ],
      "id": "en-..--..-mul-punct-gQGQbjDb",
      "links": [
        [
          "?",
          "?#Translingual"
        ],
        [
          "question mark",
          "question mark"
        ]
      ],
      "raw_tags": [
        "punctuation"
      ],
      "tags": [
        "alt-of",
        "morse-code",
        "visual-rendering"
      ]
    }
  ],
  "word": "..--.."
}

{
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "punct",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "question mark",
          "word": "?"
        }
      ],
      "categories": [
        "Translingual entries with incorrect language header",
        "Translingual lemmas",
        "Translingual punctuation marks",
        "Translingual terms spelled with .",
        "Translingual terms with non-redundant manual script codes",
        "Translingual terms with redundant sortkeys"
      ],
      "glosses": [
        "Visual rendering of Morse code for ? (“question mark”)."
      ],
      "links": [
        [
          "?",
          "?#Translingual"
        ],
        [
          "question mark",
          "question mark"
        ]
      ],
      "raw_tags": [
        "punctuation"
      ],
      "tags": [
        "alt-of",
        "morse-code",
        "visual-rendering"
      ]
    }
  ],
  "word": "..--.."
}