開あいた口くちが塞ふさがらぬ

expression, noun-modifying (irregular)

jaw-dropping; shocking; surprising

Idiomatic expression describing something so surprising or shocking that one's mouth stays open in astonishment. Often used prenominally to modify a noun.

See also: 開いた口も塞がらぬ

• 彼かれの突とつ然ぜんの辞じ職しょくは、あいた口くちが塞ふさがらぬニュースだった。

  His sudden resignation was jaw-dropping news.

• その光こう景けいを見みて、あいた口くちが塞ふさがらぬ思おもいだった。

  Seeing that sight, I was utterly shocked.