a comical expression of surprise used in the popular 2006 movie, Borat, and copied in various parodies including Yu Gi Oh, the Abridged series.
Doctor: you have cancer
Guy who's just watched Borat: wowawewa!
Doctor: I'm serious.
Guy who's just watched Borat: so what, I have Ipod, you have ipod mini, everyone know ipod mini is for girls!!!
Doctor: you know what else?
Guy who's just watched Borat: what?
Doctor:your an idiot