"without trace" meaning in English

{
  "lang": "English",
  "lang_code": "en",
  "pos": "prep_phrase",
  "senses": [
    {
      "alt_of": [
        {
          "word": "without a trace"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              122,
              135
            ]
          ],
          "ref": "1959 March 6, “New Railways in Quebec”, in Railway Magazine, page 202:",
          "text": "Work on the muskeg resulted in the formation in the first instance, and later in lengths of newly-laid track disappearing without trace into the treacherous bog.",
          "type": "quotation"
        },
        {
          "bold_text_offsets": [
            [
              104,
              117
            ]
          ],
          "ref": "2021 May 5, Philip Haigh, “I think we need better than this from the rail industry”, in RAIL, number 930, page 51:",
          "text": "It's true that NR did submit plans for Castlefield to DfT, but that was back in 2015 and they have sunk without trace.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Alternative form of without a trace."
      ],
      "id": "en-without_trace-en-prep_phrase-WlhcMKlE",
      "links": [
        [
          "without a trace",
          "without a trace#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "without trace"
}

{
  "lang": "English",
  "lang_code": "en",
  "pos": "prep_phrase",
  "senses": [
    {
      "alt_of": [
        {
          "word": "without a trace"
        }
      ],
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English prepositional phrases",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              122,
              135
            ]
          ],
          "ref": "1959 March 6, “New Railways in Quebec”, in Railway Magazine, page 202:",
          "text": "Work on the muskeg resulted in the formation in the first instance, and later in lengths of newly-laid track disappearing without trace into the treacherous bog.",
          "type": "quotation"
        },
        {
          "bold_text_offsets": [
            [
              104,
              117
            ]
          ],
          "ref": "2021 May 5, Philip Haigh, “I think we need better than this from the rail industry”, in RAIL, number 930, page 51:",
          "text": "It's true that NR did submit plans for Castlefield to DfT, but that was back in 2015 and they have sunk without trace.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Alternative form of without a trace."
      ],
      "links": [
        [
          "without a trace",
          "without a trace#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "without trace"
}