D.F.U. 

Don't Fuck Up

From "Fair Game" (2010):

INT. CORRIDOR. LANGLEY. DAY.

Valerie walks with MIKE and BILL, their chief.

BILL

Val, seventh floor have issued a

directive for a Joint Task Force on

Iraq. We want you to head it up.

Valerie doesn't blink.

VALERIE

Yes Sir.

BILL

You can pick your team. This is top

priority. Down the line D.F.U.

VALERIE

What about the Dubai op?

BILL

Mike says you got a hunch on the

buyer.

VALERIE

Manucher Vaziri. Syrian National.

Based out of Karachi. On a wire

picked up in Cairo he talks about

componentry from a known source in

Pakistan he's moving to an unnamed

Gulf state..

BILL

Iraq?

VALERIE

Vaziri's devoutly Shia. Iraq's

controlled by the Sunni. Saddam's

Sunni. There's no way this is Iraq.

BILL

They're all good Muslims right?

VALERIE

And Martin Luther King and the KKK

are both Christian.

BILL

Great job. From Monday, I need you

both eyes on Iraq.

CUT TO:

At the door, they shake hands. Mike and Valerie walk off.

MIKE

D.F.U?

VALERIE

Don't fuck up.

D.F.U. by outadabronx May 31, 2011

Duff (D.U.F.F.) 

abv. for Designated Ugly Fat Friend; Term men use to describe a fatter, less attractive friend, a woman brings with her to a party or social gathering to make herself look better by comparison. In some cases the more attractive woman will not "put out" for any male, unless one of his friends "takes one for the team" and "hits" the Duff.

C'mon take one for the team and hit that Duff (D.U.F.F.), I'll buy you lunch tomorrow!

Duff (D.U.F.F.) by Dr. Slappy McGee III Esq. March 19, 2006

D.G.I.F.U 

An acronym for 'Don't Get It Fucked Up' from the Chris Brown x Tyga album, 'Fan Of A Fan: The Album'. The song D.G.I.F.U also features Pusha T.

Guy 1: You need to stop fronting, you're finished here.
Guy 2: Stfu dude, I could buy this whole city if I wanted!
Guy 1: D.G.I.F.U, you don't have a stack of cash or a flashy pad, I saw you last week driving a taxi cab. Stop tryna make people thing you're loaded.
Guy 2: Uhm *walks away defeated*

D.G.I.F.U by ballinonem June 19, 2016

D.U.F.F. 

An abbreviation for 'Designated Ugly Fat Friend'. Often in many large groups of women (usually adolecents) there will be a D.U.F.F. as a means to look better by comparison.

I only hang out with her becuase I need a D.U.F.F., otherwise, she'd be, so, history.

D.U.F.F. by B.a.m December 21, 2005

D.U.F.F. 

The Designated (/Dumb) Ugly Fat Friend.

The cock-blocking friend of the hot chick you're trying to hook up with, often the target of the wingman.

I was totally in with this chick and then her D.U.F.F. totally cock-blocked me!

-or-

I'll take her, while you distract her D.U.F.F.!

D.U.F.F. by Victory2FuManchu September 7, 2006

D.U.F. 

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.

D.U.F. by Cheyenne Low October 18, 2008

D.U.F.A 

Designated Ugly Fat Ass

Ew look at that D.U.F.A

D.U.F.A by J.D.R August 25, 2009