2022 · bust a nut (third-person singular simple present busts a nut, present participle busting a nut, simple past and past participle busted a nut or bust a nut) (idiomatic, slang, vulgar) To ejaculate. (idiomatic, slang, vulgar) To work very hard; to put in a lot of effort. Synonyms (eject semen): bust, nut; see also Thesaurus:ejaculate.