"buttock-clenching" meaning in English

{
  "forms": [
    {
      "form": "more buttock-clenching",
      "tags": [
        "comparative"
      ]
    },
    {
      "form": "most buttock-clenching",
      "tags": [
        "superlative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "buttock-clenching (comparative more buttock-clenching, superlative most buttock-clenching)",
      "name": "en-adj"
    }
  ],
  "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2012, Michela Wrong, I Didn’t Do It For You, page 19:",
          "text": "At the end of a buttock-clenching trip, we landed to find Eritrean helicopters crouched on the tarmac of an airport that had just been bombed by Ethiopian jets.",
          "type": "quote"
        },
        {
          "ref": "2019, John Aston, Driven:",
          "text": "I would zoom through the uphill left-hander at Coppice at a buttock-clenching 90mph (145km/h) in fourth, but on the climb up to Charlies the revs would fall away and third was needed just to maintain speed up the hill.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Suspenseful, frightening; causing anxiety."
      ],
      "id": "en-buttock-clenching-en-adj-qfivIsho",
      "links": [
        [
          "Suspenseful",
          "suspenseful"
        ],
        [
          "frightening",
          "frightening"
        ],
        [
          "anxiety",
          "anxiety"
        ]
      ],
      "raw_glosses": [
        "(informal) Suspenseful, frightening; causing anxiety."
      ],
      "synonyms": [
        {
          "tags": [
            "North-America"
          ],
          "word": "butt-clenching"
        },
        {
          "word": "frightening"
        }
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "buttock-clenching"
}

{
  "forms": [
    {
      "form": "more buttock-clenching",
      "tags": [
        "comparative"
      ]
    },
    {
      "form": "most buttock-clenching",
      "tags": [
        "superlative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "buttock-clenching (comparative more buttock-clenching, superlative most buttock-clenching)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English informal terms",
        "English lemmas",
        "English multiword terms",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "2012, Michela Wrong, I Didn’t Do It For You, page 19:",
          "text": "At the end of a buttock-clenching trip, we landed to find Eritrean helicopters crouched on the tarmac of an airport that had just been bombed by Ethiopian jets.",
          "type": "quote"
        },
        {
          "ref": "2019, John Aston, Driven:",
          "text": "I would zoom through the uphill left-hander at Coppice at a buttock-clenching 90mph (145km/h) in fourth, but on the climb up to Charlies the revs would fall away and third was needed just to maintain speed up the hill.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Suspenseful, frightening; causing anxiety."
      ],
      "links": [
        [
          "Suspenseful",
          "suspenseful"
        ],
        [
          "frightening",
          "frightening"
        ],
        [
          "anxiety",
          "anxiety"
        ]
      ],
      "raw_glosses": [
        "(informal) Suspenseful, frightening; causing anxiety."
      ],
      "synonyms": [
        {
          "tags": [
            "North-America"
          ],
          "word": "butt-clenching"
        },
        {
          "word": "frightening"
        }
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "buttock-clenching"
}