"headslapper" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "head",
        "3": "slapper"
      },
      "expansion": "head + slapper",
      "name": "compound"
    }
  ],
  "etymology_text": "From head + slapper.",
  "forms": [
    {
      "form": "headslappers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "headslapper (plural headslappers)",
      "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": [
        "A mistake of obvious stupidity."
      ],
      "id": "en-headslapper-en-noun-brxTAIRV",
      "links": [
        [
          "mistake",
          "mistake"
        ],
        [
          "obvious",
          "obvious"
        ],
        [
          "stupidity",
          "stupidity"
        ]
      ],
      "raw_glosses": [
        "(informal) A mistake of obvious stupidity."
      ],
      "related": [
        {
          "word": "d'oh"
        },
        {
          "word": "as an exclamation"
        },
        {
          "word": "facepalm"
        },
        {
          "word": "a related gesture"
        }
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "headslapper"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "head",
        "3": "slapper"
      },
      "expansion": "head + slapper",
      "name": "compound"
    }
  ],
  "etymology_text": "From head + slapper.",
  "forms": [
    {
      "form": "headslappers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "headslapper (plural headslappers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "d'oh"
    },
    {
      "word": "as an exclamation"
    },
    {
      "word": "facepalm"
    },
    {
      "word": "a related gesture"
    }
  ],
  "senses": [
    {
      "categories": [
        "English compound terms",
        "English countable nouns",
        "English entries with incorrect language header",
        "English informal terms",
        "English lemmas",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "A mistake of obvious stupidity."
      ],
      "links": [
        [
          "mistake",
          "mistake"
        ],
        [
          "obvious",
          "obvious"
        ],
        [
          "stupidity",
          "stupidity"
        ]
      ],
      "raw_glosses": [
        "(informal) A mistake of obvious stupidity."
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "headslapper"
}