あんぐり

adverb, noun-modifying (irregular)

open-mouthed; agape

Describes a state of having one's mouth wide open, often from surprise, shock, or disbelief. Commonly used with する or as an adverb modifying verbs like 見る.

• その光こう景けいを見みて、あんぐりと口くちを開あけた。

  Seeing that sight, I opened my mouth wide in amazement.

• 彼かれはあんぐりした顔かおでニュースを聞きいていた。

  He was listening to the news with his mouth agape.