BK 

stands for Boner killer. when a girl is so ugly that when you think of her your wood instantly goes away.

louis: yo did you see the girl over there?
Bruce: yo she's a BK

BK by vindcated March 20, 2010

bk 

What cribs substitute for "b" whenever they type online. Pretty funny if they type a long ass paragraph. Common on friendster and myspace.

wut up Cuh, i bke bkangin bklue all day and fuCcin up dem slobk ass niggaz every night

C's up
hoe's down

bk by LkJ January 4, 2005

BK 

An abbreviation for "Bad Kid" incompetent gamers use when their vocabulary range is extremely low. Not only does it sound stupid but it also makes them look childish. It is generally used by people who take the game way to seriously and think they are pro because they can sit on their ass and move their thumbs.

Your a BK scrub because you killed me and i should never die because i am god at this game!

BK by revitup360 October 8, 2011

bk 

A word used by angry halo players who are mad at people that purposely try to ruin the game. The players that use this term try to make 1-9128128 new slang terms daily because they thinks it makes them cool.

You are such a bk for shooting me in the back and getting that free betrayl

bk by 1999566435 August 14, 2010

bk 

Normaly used in online text chat convos, meaning "back"

Josh: 1 second some-ones at the door!
Dom: k
Josh: ok i'm bk
Josh: It was a mate from down the road.

bk by Josh July 30, 2004

BK 

Usually used by people from Brooklyn who have stepped out of their turf and are liable to receive a giant ass-kicking as well as their three other BK friends down in the dirty dirty.

Also a Blood Killer.

Yo dat nigga over der be from BK lets talk to em and become his homeboy. Oh shit, hurr come dem dirtys.

BK by Carol City Boy May 13, 2005

bk 

Burger King-Have it your way

Thanks for choosing BK proceed to the next window.

bk by Kevin February 24, 2005