1 general:: Phrase(s): keep an act up [and] keep one’s act up to maintain behavior that is a false show; to continue with one’s facade. (The an can be replaced with the, this, that, etc.) • How long do I have to keep this act up? I am tired of fooling people. • I am weary of keeping up my act.
McGrawhill's American Idioms And Phrasal Verbs