Definition of smart-arse in English:
A person who is irritating because they behave as if they know everything.
- I'm not a smart-arse who thinks he knows all the answers now, far from it.
- Cutting, heavily ironic comedy and musical numbers ensue, best appreciated for their dazzling cleverness, not for their smart-ass, apathetic politics.
- You could call Lee a smart-ass but he is too clever for that.