keep one's mouth shut

verb

(idiomatic) To keep a secret; to refrain from speaking indiscreetly or carelessly; broadly, to refrain from speaking altogether.

I promised to keep my friend's secret, so I will keep my mouth shut.

意味（1）

(idiomatic) To keep a secret; to refrain from speaking indiscreetly or carelessly; broadly, to refrain from speaking altogether.

He thought that he could get him a regular salary if he would come to Packingtown and do as he was told, and keep his mouth shut.