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".