腰こしが砕くだける

expression, ichidan verb

collapse; give way; lose one's nerve

Idiomatic expression meaning to lose physical strength in the lower body, or figuratively to lose resolve or give up under pressure. Often used when someone's legs buckle or they become unable to stand firm.

See also: 腰砕け (こしくだけ)

• あまりの衝しょう撃げきに腰こしが砕くだけて座すわり込こんでしまった。

  The shock was so great that my knees gave way and I sank to the ground.

• 彼かれは上じょう司しに厳きびしく言いわれて腰こしが砕くだけた。

  He lost his nerve when his boss scolded him harshly.