"last thing" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "last thing (not comparable)",
      "name": "en-adv"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Times of day",
          "orig": "en:Times of day",
          "parents": [
            "Periodic occurrences",
            "Timekeeping",
            "Time",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2010, Michael Oliver, Tales from the Toolbox",
          "text": "Denis Daviss agrees that practice session timing had a lot to do with it; this was a particular issue at Monaco due to the fact that the circuit was on public roads, so sessions were held first thing in the morning and last thing at night",
          "type": "quotation"
        }
      ],
      "glosses": [
        "late in the day"
      ],
      "id": "en-last_thing-en-adv-um04hM1F",
      "raw_glosses": [
        "(idiomatic) late in the day"
      ],
      "related": [
        {
          "word": "first thing"
        },
        {
          "word": "if it's the last thing I do"
        }
      ],
      "tags": [
        "idiomatic",
        "not-comparable"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-last thing.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/0/09/En-au-last_thing.ogg/En-au-last_thing.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/0/09/En-au-last_thing.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "last thing"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "last thing (not comparable)",
      "name": "en-adv"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adv",
  "related": [
    {
      "word": "first thing"
    },
    {
      "word": "if it's the last thing I do"
    }
  ],
  "senses": [
    {
      "categories": [
        "English adverbs",
        "English entries with incorrect language header",
        "English idioms",
        "English lemmas",
        "English multiword terms",
        "English terms with audio links",
        "English terms with quotations",
        "English uncomparable adverbs",
        "en:Times of day"
      ],
      "examples": [
        {
          "ref": "2010, Michael Oliver, Tales from the Toolbox",
          "text": "Denis Daviss agrees that practice session timing had a lot to do with it; this was a particular issue at Monaco due to the fact that the circuit was on public roads, so sessions were held first thing in the morning and last thing at night",
          "type": "quotation"
        }
      ],
      "glosses": [
        "late in the day"
      ],
      "raw_glosses": [
        "(idiomatic) late in the day"
      ],
      "tags": [
        "idiomatic",
        "not-comparable"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-last thing.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/0/09/En-au-last_thing.ogg/En-au-last_thing.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/0/09/En-au-last_thing.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "last thing"
}