__ up; misbehave
I believe the answer is:
act
(Other definitions for act that I've seen before include "Perform(ance)" , "Routine" , "Assumed attitude" , "Accomplishment" , "Parliamentary decree" .)
I've seen this clue in The Mirror.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free.
Check out my app
or
learn more
about the Crossword Genius project.