An Onomatopoeia. Pronunciation: haa-wuht. It's a noise/sound/whatever you make to acknowledge someone as being stupid and to insult them. However, it's very lenient in usage. You can use it to show indifference, boredom, or just about anything to insult someone.
ex 1: Herbert comes in wearing a green shirt and purple pants.
Jim: Dude, what's up?
Riley: Not much, you?
Jim: I'm ecstatic! I just got a girlfriend!
Pip: Hey you wanna come over?
Mike: and do what?
Pip: We can play my new nintendo DS and eat some popcorn!
by Luke Lay January 16, 2009