愚ぐの骨こっ頂ちょう

expression, noun

the height of folly; sheer stupidity

Idiomatic expression used to criticize an action or idea as extremely foolish. Often used in formal or written contexts.

• そんな計けい画かくを進すすめるなんて愚ぐの骨こっ頂ちょうだ。

  Pushing ahead with such a plan is the height of folly.

• 彼かれの提てい案あんは愚ぐの骨こっ頂ちょうと言いわざるを得えない。

  I have to say his proposal is sheer stupidity.