"con comme un manche" meaning in French

{
  "etymology_templates": [
    {
      "args": {
        "1": "dumb/thick as a handle/broomstick"
      },
      "expansion": "“dumb/thick as a handle/broomstick”",
      "name": "m-g"
    },
    {
      "args": {
        "1": "dumb/thick as a handle/broomstick"
      },
      "expansion": "Literally, “dumb/thick as a handle/broomstick”",
      "name": "lit"
    }
  ],
  "etymology_text": "Literally, “dumb/thick as a handle/broomstick”.",
  "forms": [
    {
      "form": "conne comme un manche",
      "tags": [
        "feminine"
      ]
    },
    {
      "form": "cons comme des manches",
      "tags": [
        "masculine",
        "plural"
      ]
    },
    {
      "form": "connes comme des manches",
      "tags": [
        "feminine",
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "fp": "connes comme des manches",
        "mp": "cons comme des manches"
      },
      "expansion": "con comme un manche (feminine conne comme un manche, masculine plural cons comme des manches, feminine plural connes comme des manches)",
      "name": "fr-adj"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "French entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "French similes",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Very stupid; thick as a brick; dumb as a post"
      ],
      "id": "en-con_comme_un_manche-fr-adj-Tr39lKsI",
      "links": [
        [
          "thick as a brick",
          "thick as a brick"
        ],
        [
          "dumb as a post",
          "dumb as a post"
        ]
      ],
      "qualifier": "simile",
      "raw_glosses": [
        "(simile, vulgar) Very stupid; thick as a brick; dumb as a post"
      ],
      "synonyms": [
        {
          "word": "bête à manger du foin"
        },
        {
          "word": "bête comme ses pieds"
        },
        {
          "word": "con comme la lune"
        },
        {
          "word": "con comme un balai"
        }
      ],
      "tags": [
        "vulgar"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/kɔ̃ kɔ.m‿œ̃ mɑ̃ʃ/"
    },
    {
      "audio": "LL-Q150 (fra)-Lepticed7-con comme un manche.wav",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/ef/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/ef/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav.ogg",
      "text": "Audio"
    }
  ],
  "word": "con comme un manche"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "dumb/thick as a handle/broomstick"
      },
      "expansion": "“dumb/thick as a handle/broomstick”",
      "name": "m-g"
    },
    {
      "args": {
        "1": "dumb/thick as a handle/broomstick"
      },
      "expansion": "Literally, “dumb/thick as a handle/broomstick”",
      "name": "lit"
    }
  ],
  "etymology_text": "Literally, “dumb/thick as a handle/broomstick”.",
  "forms": [
    {
      "form": "conne comme un manche",
      "tags": [
        "feminine"
      ]
    },
    {
      "form": "cons comme des manches",
      "tags": [
        "masculine",
        "plural"
      ]
    },
    {
      "form": "connes comme des manches",
      "tags": [
        "feminine",
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "fp": "connes comme des manches",
        "mp": "cons comme des manches"
      },
      "expansion": "con comme un manche (feminine conne comme un manche, masculine plural cons comme des manches, feminine plural connes comme des manches)",
      "name": "fr-adj"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "French adjectives",
        "French entries with incorrect language header",
        "French lemmas",
        "French multiword terms",
        "French similes",
        "French terms with IPA pronunciation",
        "French terms with audio links",
        "French vulgarities"
      ],
      "glosses": [
        "Very stupid; thick as a brick; dumb as a post"
      ],
      "links": [
        [
          "thick as a brick",
          "thick as a brick"
        ],
        [
          "dumb as a post",
          "dumb as a post"
        ]
      ],
      "qualifier": "simile",
      "raw_glosses": [
        "(simile, vulgar) Very stupid; thick as a brick; dumb as a post"
      ],
      "synonyms": [
        {
          "word": "bête à manger du foin"
        },
        {
          "word": "bête comme ses pieds"
        },
        {
          "word": "con comme la lune"
        },
        {
          "word": "con comme un balai"
        }
      ],
      "tags": [
        "vulgar"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/kɔ̃ kɔ.m‿œ̃ mɑ̃ʃ/"
    },
    {
      "audio": "LL-Q150 (fra)-Lepticed7-con comme un manche.wav",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/ef/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/e/ef/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav/LL-Q150_%28fra%29-Lepticed7-con_comme_un_manche.wav.ogg",
      "text": "Audio"
    }
  ],
  "word": "con comme un manche"
}