bust one’s ass to do something

bust (one's) ass

1. rude slang (acting upon oneself) To exert a significant amount of energy or work very hard to do, accomplish, or complete something. I've been busting my ass all night long to get this presentation ready for tomorrow's meeting. She's going to have to bust her ass if she wants a place on the varsity team.
2. rude slang (acting upon someone else) To harass, nag, or upbraid someone to do, accomplish, or complete something. The boss is busting everyone's ass to get the project ready by next week. Quit busting my ass! I'll get it done eventually!
See also: ass, bust

bust (one’s) ass (to do something)

and break (one’s) balls (to do something) and bust (one’s) butt (to do something) and bust (one’s) nuts (to do something)
tv. to work very hard to do something; to work very hard at something. (Usually objectionable.) You get down there and bust your ass to get the job done right! You hear me? I busted my butt to please her, and what do I get?
See also: ass, bust, something