狂気の沙汰

sheer madness

→ 狂気
phrase Rare #35,263
sheer madness An idiomatic expression describing something extremely reckless, irrational, or outrageous. It can be used seriously or dramatically, and is often followed by だ.
JA: こんな寒い日に泳ぐなんて、狂気の沙汰だ。
EN: Swimming on such a cold day is sheer madness.

冬にあの山に登るのは狂気の沙汰

Climbing that mountain in winter is sheer madness.

狂気の沙汰

That’s insane.

— オデッセイ (2015)

彼の行為はまさしく狂気の沙汰だった

What he did was nothing short of madness.

君を知りもせず狂気の沙汰だと思うだろう

They’d think it was madness without even knowing you.

— ラブ・アクチュアリー (2003)

これは狂気の沙汰だぞ

This is madness.

— パンズ・ラビリンス (2006)