Noun
a demanding woman who destroys men's confidence
a job or situation that is demanding and arduous and punishing
Source: WordNetAlright, macho babe boy, I'm not some little ditz to bat my eyelashes at the buff stud in black leather. Don't try your he-man tactics with me. I'll have you know, in my office, I'm known as the ball-breaker. (Amanda) Sherrilyn Kenyon
Vietnam was a ball-breaker Source: Internet