Pipe down and Shut one's mouth

Pipe down verb - To become still and orderly.

Shut one's mouth and pipe down are semantically related. in shut up topic. In some cases you can use "Shut one's mouth" instead a verb "Pipe down".

Shut one's mouth verb - Refrain from divulging sensitive information; keep quiet about confidential information.

Pipe down and shut one's mouth are semantically related. Sometimes you can use "Pipe down" instead a verb phrase "Shut one's mouth".