"dead as a doorknob" meaning in English

{
  "etymology_text": "Possibly from a misinterpretation or misunderstanding of the expression dead as a doornail. See usage notes below.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "adjective"
      },
      "expansion": "dead as a doorknob",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English similes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Entries with translation boxes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Danish translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Finnish translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Norwegian Bokmål translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Death",
          "orig": "en:Death",
          "parents": [
            "Body",
            "Life",
            "All topics",
            "Nature",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "I tried the flashlight, but the battery was as dead as a doorknob.",
          "type": "example"
        },
        {
          "text": "I found the mouse who lived in our wall, lying on his back with his feet in the air—as dead as a doorknob.",
          "type": "example"
        }
      ],
      "glosses": [
        "Entirely, unquestionably or certainly dead."
      ],
      "id": "en-dead_as_a_doorknob-en-adj-4cBVven3",
      "links": [
        [
          "Entirely",
          "entirely"
        ],
        [
          "unquestionably",
          "unquestionably"
        ],
        [
          "dead",
          "dead"
        ]
      ],
      "qualifier": "simile",
      "raw_glosses": [
        "(simile) Entirely, unquestionably or certainly dead."
      ],
      "translations": [
        {
          "code": "da",
          "lang": "Danish",
          "sense": "unquestionably dead (see here)",
          "word": "død som en sild"
        },
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "unquestionably dead (see here)",
          "word": "kuollut kuin kivi"
        },
        {
          "code": "nb",
          "english": "dead as a herring",
          "lang": "Norwegian Bokmål",
          "sense": "unquestionably dead (see here)",
          "word": "død som en sild"
        }
      ]
    }
  ],
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      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/6/6a/En-au-dead_as_a_doorknob.ogg"
    }
  ],
  "word": "dead as a doorknob"
}

{
  "etymology_text": "Possibly from a misinterpretation or misunderstanding of the expression dead as a doornail. See usage notes below.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "adjective"
      },
      "expansion": "dead as a doorknob",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English similes",
        "English terms with usage examples",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Danish translations",
        "Terms with Finnish translations",
        "Terms with Norwegian Bokmål translations",
        "en:Death"
      ],
      "examples": [
        {
          "text": "I tried the flashlight, but the battery was as dead as a doorknob.",
          "type": "example"
        },
        {
          "text": "I found the mouse who lived in our wall, lying on his back with his feet in the air—as dead as a doorknob.",
          "type": "example"
        }
      ],
      "glosses": [
        "Entirely, unquestionably or certainly dead."
      ],
      "links": [
        [
          "Entirely",
          "entirely"
        ],
        [
          "unquestionably",
          "unquestionably"
        ],
        [
          "dead",
          "dead"
        ]
      ],
      "qualifier": "simile",
      "raw_glosses": [
        "(simile) Entirely, unquestionably or certainly dead."
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-dead as a doorknob.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/6/6a/En-au-dead_as_a_doorknob.ogg/En-au-dead_as_a_doorknob.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/6/6a/En-au-dead_as_a_doorknob.ogg"
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  ],
  "translations": [
    {
      "code": "da",
      "lang": "Danish",
      "sense": "unquestionably dead (see here)",
      "word": "død som en sild"
    },
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "unquestionably dead (see here)",
      "word": "kuollut kuin kivi"
    },
    {
      "code": "nb",
      "english": "dead as a herring",
      "lang": "Norwegian Bokmål",
      "sense": "unquestionably dead (see here)",
      "word": "død som en sild"
    }
  ],
  "word": "dead as a doorknob"
}