Abv. For Designated Ugly Fat Friend. Usually the one person more approachable in a group and the one who is less attractive than all the others in the group. Sometimes a girl will approach a DUFF and start to flirt but after a while will begin to ask questions about another hotter member of the group.
Man #1: Dude, that's your job as the DUFF
Man#2: What did you just say to me?
Man#1: You're a DUFF, Designated Ugly Fat Friend.
Man#2: That's so messed up.
Man#2: What did you just say to me?
Man#1: You're a DUFF, Designated Ugly Fat Friend.
Man#2: That's so messed up.
by Sugary sweet April 07, 2017