the duff 

the Designated, Ugly, Fat, Friend. Everyone has one in their group of friends. shes the easiest person to talk to in the group, shes the one to go to when a guy needs to find out where the fit girl in the squad likes to eat out at.

shes the DUFF in our squad

the duff by Trafford112 April 11, 2015

The Duff 

Designated Ugly Fat Friend. A book written by Kody Keplinger. Also a movie. Basically it's the person in a group of friends that is less popular than the rest, isn't as pretty/handsome, or they are a bit thicker than the rest. Sometimes it can be a freshman with a group of juniors or seniors. The Duff can be someone other people go to to get information on the Duff's hotter friends.

Emily = The Duff
Hot guy : Yo Emily!

Emily : *omg a hot guy is actually talking to me!!*
Hot guy : hey, do you know if your friend Hannah has a date to homecoming? I want to ask her to go with me.

The Duff by NWinchester April 23, 2016

The Duff 

When you are fucking a girl for the first time anally, you pull out too fast and the girl begins to shit uncontrollably.

Person 1: Dude OMG I heard you got with (girl's name) last night ..
Person 2: Yeah I'd rather not talk about it, it was a bad case of The Duff.

The Duff by The Duff Veteran November 10, 2010

The DUFF 

Designated Ugly Fat Fuck

Dang, look at the girls. Kimberly must be The DUFF.

The DUFF by slickbick September 6, 2016

The Duff 

A person of great power and an ardent supporter and believer in Polygamy who enjoys the company of three or four women rather than one

Your man over there has 6 Putinis around his waist he’s doing The Duff

The Duff by Pimp Daddy Mack October 4, 2018

The duff 

Designated ugly fat friends

That one friend group that everbody avoides for obvious reasons

The people that sit near the benches at school are the Duffs of school

The duff by Smonky August 21, 2021

up the duff 

To be pregnant.

It was very embarrssing for Kevin when he got Peggy up the duff, but it served him right for trying to save money by using a flak jacket.

up the duff by Dunky Oggins December 7, 2003