Supa Fly is a term for high, the state one becomes after smoking pot. This term comes from Portland Oregon, although I have heard it in Seattle.
Supa Fly can also be used as cool, although this is rarely used anymore.
After I smoked that dime bag, I was sooo supa fly I could barely walk.
A woman who is extremely beautiful
You that chick was supa fly when she bounced that badunkadunk through the room