"Bad Thing" meaning in English

{
  "etymology_text": "Originally from the 1930 book 1066 And All That by W.C. Sellar & R.J. Yeatman, popularized through hacker culture.",
  "forms": [
    {
      "form": "Bad Things",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "Bad Thing"
      },
      "expansion": "Bad Thing (plural Bad Things)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "An action that yields undesirable results to its subject."
      ],
      "id": "en-Bad_Thing-en-noun-y9-uzrdJ",
      "raw_glosses": [
        "(informal) An action that yields undesirable results to its subject."
      ],
      "related": [
        {
          "word": "Good Thing"
        }
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "Bad Thing"
}

{
  "etymology_text": "Originally from the 1930 book 1066 And All That by W.C. Sellar & R.J. Yeatman, popularized through hacker culture.",
  "forms": [
    {
      "form": "Bad Things",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "Bad Thing"
      },
      "expansion": "Bad Thing (plural Bad Things)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "Good Thing"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English informal terms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "An action that yields undesirable results to its subject."
      ],
      "raw_glosses": [
        "(informal) An action that yields undesirable results to its subject."
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "Bad Thing"
}