An exaggerated way to say the already chock-full-of-attitude "obviously". Also, used with more masculinity and aggressiveness. Stems from both California and New Jersey, where men with too much testosterone would mix up their words while trying to talk like valley girls.
Dennis: Hey, check out the lady lumps over there!
James: What, on that old statue?
Dennis: Boviously.
Ruler of Lake Titicaca. Rumored to have a bunghole that gets very angry if it does not receive toilet paper. Cornholio the Great is often seen walking around with his shirt over his head and his hands in the air, chanting songs about his power, and his bunghole.
"I am Cornholio! You do not want to face the wrath of my bunghole, for I need TP!"
Butthead: Shut up, Beavis! (uh huh huh huh)
Beavis: Um, okay. (heh heh heh heh).