1. basically means to claifify something....
2. to be sure of something.
1. boy: you paid $15000 fo yo watch?!
pimp : know dat bitch!!!
2. steve: awww man! I gotta work @ 4 and I'm late my boss is gonna be mad as hell when I get to work.
steve's boss: * as steve walks thru the door 2 hrs late*
steve: I'm late..
steve's boss: know dat! now sign this write up
3. boy: I'm broke and payday isn't till thurs
girl: me to! know dat