look up any word, like swag:
Big Ugly Fat Fuck, aka, that annoying guy who considers himself to be all that, but in reality said person is just a douche bag. The term is typically used in veiled sarcasm by everyone else around said person, since he is far too oblivious to the intended meaning.
Troy: "Hey Jerry, you're looking pretty B.U.F.F. there, you been working out?"

Jerry: "What? Nah, I'm just naturally this way."

Steve: (to Troy, after Jerry walks away) "Did you really mean that?"

Troy: "Yep, he really is a Big Ugly Fat Fuck"
by Erkadurka June 09, 2011
Sorta like the term D.U.F.F, meaning designated ugly fat friend, the word B.U.F.F means, black ugly fat friend.
Girl 1: Hey do you want to hang out later?
Girl 2: Yeah! Make sure you call Lisa, shes our B.U.F.F.
Girl 1: Oh, good call, I will see you girls later.
by Steet August 21, 2009
a cop that loves his job a bit too much.
sgt - aren't you supposed to be on meal?
cop - i was going, but this guy had excessively loud music coming from his car, so i threw out my whopper to write him a summons.
sgt - ...you fucking loser, stop being such a damn buff before people flip your locker.
by flipyoutoo February 15, 2008
big ugly fat friend. Every group of friends usually has one.
"Why does Sally hang out with them?"
"I don't know man, she's such a B.U.F.F.
by bma1 October 05, 2007
Muscly or fit. When you've been working out and got well defined muscles you're looking buff.
Somebody: "Did you see The Who at Live Aid?"

Somebody else: "Yeah, Daltrey was looking quite buff!"
by Makeety Makondo July 23, 2006
Big ugly fat friend. Usually refers to a freind that makes you look a whole lot better in social situations.
I,m gonna go to the bar this weekend and bring my B.U.F.F. Jeff.
by Denny D. Bat April 13, 2006
(In MMORPGs) To improve the power, speed, strength and general statistics of yourself and other players - Usually used by supportive roles such as Healers.
(Cleric)Dathimus uses (Buff)Strength II on (Warrior) Leara
by runemeds November 03, 2009