Collins COBUILD Advanced Learner's English Dictionary - smart arse

(smart arses) Note: The spellings 'smartarse' in British English and 'smartass' or 'smart-ass' in American English are also used. If you describe someone as a smart arse or smartass, you dislike the fact that they think they are very clever and like to show everyone this. (INFORMAL, RUDE) ...smartass comments. N-COUNT: oft N n c darkgreen]disapproval