keep one's mouth shut

[keep one's mouth shut] {v. phr.}, {informal} To be or stay silent.- A rude expression when used as a command.

When the crooks werecaptured by the police, their leader warned them to keep their mouthsshut.

Charles began to tell Barry how to kick the ball, and Barrysaid angrily, "Keep your mouth shut!"

Syn.: SHUT UP(1).