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1.
Duf
An acronym for Designated Ugly Friend. Every hot girl has a DUF simply to make her look that much hotter. This strategy also works for average looking girls.
Hey Bill, here comes Mary and her DUF. I call Mary!
by Ryan June 17, 2004
 
2.
DUF
Designated Ugly Friend - the one obligatory fat chick in every group of hot chicks. see running interference
Damn, all those chicks are hot except for that one. Bailey's gonna take the duff home tonight.
by AspiringdeitY August 05, 2003
 
3.
duf
designated ugly friend
"Dude that chicks UGLY!"

"Yes, she's the duf in the group."
by Stefany Nowak June 25, 2007
 
4.
Don't U Feel Silly
lol you think it's Thursday? DUFS!
by bobjoneslolz February 06, 2013
 
5.
Meaning, "Designated Ugly friend."
A pretty girl always has pretty friends, but when she wants to snag guys, she brings along her D.U.F. only.
So who is the guys going to hit on?

You get the picture.
by Cheyenne Low August 28, 2008
 
6.
duf
short for dueche fag
you shouldn't have done that you duf
by Jacob Smith February 05, 2004