break one's ass

break someone's ass . Also, bust someone's chops . Thrash or harass someone, as in Jim threatened to break Tim's ass , or The boss broke his workers' chops to improve service . [ Vulgar slang ; mid-1900s]

Exert oneself to the utmost, try extremely hard, as in I've been breaking my ass to finish early . This expression is considered vulgar slang; both ass , for backside or buttocks, and balls , for male genitals, are rude; butt , for buttocks, and chops , for either the mouth or the legs, are informal and emphatic but not quite as offensive. For a more polite synonym, see break one's back . [ Slang ; first half of 1900s]