"couper les cheveux en quatre" meaning in French

{
  "etymology_templates": [
    {
      "args": {
        "1": "cut hair in four"
      },
      "expansion": "“cut hair in four”",
      "name": "m-g"
    },
    {
      "args": {
        "1": "cut hair in four"
      },
      "expansion": "Literally, “cut hair in four”",
      "name": "lit"
    },
    {
      "args": {
        "1": "it",
        "2": "spaccare il capello in quattro"
      },
      "expansion": "Italian spaccare il capello in quattro",
      "name": "cog"
    }
  ],
  "etymology_text": "Literally, “cut hair in four”. Compare Italian spaccare il capello in quattro.",
  "head_templates": [
    {
      "args": {},
      "expansion": "couper les cheveux en quatre",
      "name": "fr-verb"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "French entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
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          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "english": "Don't split hairs. You know what I'm getting at.",
          "text": "Ne coupe pas les cheveux en quatre. Tu sais où je veux en venir.",
          "type": "example"
        }
      ],
      "glosses": [
        "to split hairs"
      ],
      "id": "en-couper_les_cheveux_en_quatre-fr-verb-AVdU5Ftd",
      "links": [
        [
          "split hairs",
          "split hairs"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) to split hairs"
      ],
      "related": [
        {
          "word": "se couper en quatre"
        }
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ku.pe le ʃ(ə).vø ɑ̃ katʁ/"
    },
    {
      "audio": "LL-Q150 (fra)-LoquaxFR-couper les cheveux en quatre.wav",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/4/41/LL-Q150_%28fra%29-LoquaxFR-couper_les_cheveux_en_quatre.wav/LL-Q150_%28fra%29-LoquaxFR-couper_les_cheveux_en_quatre.wav.mp3",
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      "text": "Audio"
    }
  ],
  "word": "couper les cheveux en quatre"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "cut hair in four"
      },
      "expansion": "“cut hair in four”",
      "name": "m-g"
    },
    {
      "args": {
        "1": "cut hair in four"
      },
      "expansion": "Literally, “cut hair in four”",
      "name": "lit"
    },
    {
      "args": {
        "1": "it",
        "2": "spaccare il capello in quattro"
      },
      "expansion": "Italian spaccare il capello in quattro",
      "name": "cog"
    }
  ],
  "etymology_text": "Literally, “cut hair in four”. Compare Italian spaccare il capello in quattro.",
  "head_templates": [
    {
      "args": {},
      "expansion": "couper les cheveux en quatre",
      "name": "fr-verb"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "verb",
  "related": [
    {
      "word": "se couper en quatre"
    }
  ],
  "senses": [
    {
      "categories": [
        "French entries with incorrect language header",
        "French idioms",
        "French lemmas",
        "French multiword terms",
        "French terms with IPA pronunciation",
        "French terms with audio links",
        "French terms with usage examples",
        "French verbs"
      ],
      "examples": [
        {
          "english": "Don't split hairs. You know what I'm getting at.",
          "text": "Ne coupe pas les cheveux en quatre. Tu sais où je veux en venir.",
          "type": "example"
        }
      ],
      "glosses": [
        "to split hairs"
      ],
      "links": [
        [
          "split hairs",
          "split hairs"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) to split hairs"
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ku.pe le ʃ(ə).vø ɑ̃ katʁ/"
    },
    {
      "audio": "LL-Q150 (fra)-LoquaxFR-couper les cheveux en quatre.wav",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/4/41/LL-Q150_%28fra%29-LoquaxFR-couper_les_cheveux_en_quatre.wav/LL-Q150_%28fra%29-LoquaxFR-couper_les_cheveux_en_quatre.wav.mp3",
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      "text": "Audio"
    }
  ],
  "word": "couper les cheveux en quatre"
}