look up any word, like darude - sandstorm:
 
1.
Greeting - Hey friend, what is going on? Contraction of "what is up fool?"
Sup foo? How's da new crib?
by scarphish April 22, 2003
 
2.
Literally, What's up, Fool. Used instead of "Good afternoon, How are you today, Sir." or "Greetings my friend, How are you? Can also be used to taunt, such as, you're not so tough, you are sort of a fool.
Tyson to Trevor Burbick "Supfoo?" after knocking him down for the third time.
by Zipponutty September 29, 2006
 
3.
its the stylish way of sayin whats up fool. Only coolpeople like myself can say it
"sup foo?"
by l_petey23 December 29, 2003