Duff 

1. Bollocks. Rubbish. Not worth a fuck.

2. The bass player of Guns n' Roses, 10 Minute Warning, Velvet Revolver

1. I cant play that duff guitar you bought, its the cheapest lump of shit I've ever seen!

I was late for work again because my duff old Ford Fiesta broke down again!

2. Uh, well... Duff McKagan plays bass.

Duff by Saviour of the real January 23, 2007

duff 

A person who by society's description doesn't fit in with their friend group, being more approachable, and the one to go to ask for their friends numbers.

Guy: Heyyyyy

Duff:(THINKING: OMG HE's TALKING TO ME> HE'S SO HOT) Yes? What

Guy: Well, i was thinking... would you like to...

Duff: Yeah...?

Guy: What's the hot girl on the left that you were talking too's number...?

duff by satan666jks May 27, 2015

duff 

The pot left over after being "smoked" in a vaporizer.

I'm gonna make some butter with this duff.

duff by Bititall June 18, 2006

DUFF 

Stands for Designated Ugly Fat Friend. A term used to describe a hot girls fat friends. Every hot girl has at least 1 Duff. Treating the Duff like a normal person may help your entry to the hot girls Vagina.

Hey, if your in with the Duff, Your in with the stuff!

DUFF by twisted_walker November 12, 2006

DUFF 

Most commonly known as the girl that your hott date has to take along with her to the x dance. Your date won't go without her so she has to come along. The whole time she gets in the way of you two. Duff stands for designated ugly fat friend. Very terrifying moments have been caused by this race of people.

Bess: "Hey, we should go to Mikes this weekend."
Kailey: "Yeah, thats a great idea. We should take someone else, just in case things get a little too weird."
Bess: "Lets take Sarah. Shes always a good conversation peice."
Sarah= DUFF= Ugly, fat, facial hair, and zits
Everything every "man" wants

DUFF by Stanely Jr. October 9, 2005

duff 

UK Prison slang for sponge pudding.

I hope we have duff and custard tonite.

duff by pRoPeR-eNgLiSh December 27, 2008

Duff 

The butt

Only some new age duffhole would change the meaning of duff to dumb ugly fat friend or some dumb bloke’s puddin’

Duff by Phil Logenist March 13, 2019