1.A incognito way to compliment a nice behind without being heard or looked at by the selective the female target.the term started in NJ in the summer of 2007 and is now being used by college students,frat brothers and perverts up and down the east coast!
2.Nice Biground mound of butt that defies the laws of physics.
1.Jimmy have you seen "Billy Duff"? (while pointing out a target)
2.I was strolling down the beach earlier and saw a "Duff".
3. "Duff" to the right!
4. That's quite a large "duff".
A unattractive female who is always seen with another female who is marginally more attractive. It is usually impossible to score with the hotter female without the duff receiving her fair share of the action.
Damn! I so wanna tap that chick.. but goddamn, she always has that duff Nicole hanging off her. Look at that fat mess!