deff 

1. A shorter verson of definitely.

2. One who can't hear shit.

3. A definition on urbandictionary.com.

1. "hey, dude, you should deff come over"

2. "i can't hear shit i'm so deff"

3. "go look at the deff for deff on UD"

deff by joeybnukkas April 21, 2007

deff 

A shorter version of definitely .

Jessica: (Takes pencil)
Teacher: Class, pick up your pencils and begin your test.
Kathy: Oh, but i was deff using that pencil tho!

:-) , coming from a person who uses the word ALOT !

deff by Breezyyyy March 16, 2010

deff 

shortend version of "deffinitly". mainly used by asshats who don't like to spell out words on aim.

joe: you should deff come over
bob: fuck you.

deff by asshat CJ March 21, 2007

Deff 

Deff- originating in georgia, meaning Designated Extremely Fat Friend. Used primarily when u and your buddies see a hot chick with a fat friend.

guy one "damn you see that girl"
guy two" which one"
guy one "the one thats behind the Deff"
guy two"ok got ya yah shes straight"

Deff by Chris Nix October 16, 2008

Deff 

A rap group with brutal lyrics, and no production.

Current members:
Deff Nigger- vocals
Bleyend Chink- Beats/backup vocals

www.myspace.com/deffnigga

Deff by Bleyend January 8, 2009

Deff 

Short way to say definitely.

That's deff not cool.

Deff by yayno February 25, 2017

deff 

when a person heard negative decibels.

"he is a idiot, he must be deff"

deff by 1337-zorz May 7, 2008