button one's lip also zip one's lip {v. phr.}, {slang}
To stop talking; keep a secret; shut your mouth; be quiet.
The man was getting loud and insulting and the cop told him to button his lip.
John wanted to talk, but Dan told him to keep his lip buttoned.
Syn.: KEEP ONE'S MOUTH SHUT, SHUT UP. Categories: {slang} {v. phr.}