jk 

Just kidding. Used at the end of a sentence to make it completely void, therefore contributing nothing to the conversation and wasting everyone's time.
Therefore used mainly by n00bs and tards.

Tard:I hate your country, I hate your culture, and I hate your FACE! jk
Someone else: stfu

jk by Johnny The Homicidal Maniac December 28, 2005

Jk 

Shorten version of name Jungkook, member from Korean Boy Band, BTS (Bangtansonyeodan)

Jk is the youngest member of BTS. Jk is Golden Maknae.

Jk by GoodGirl March 7, 2020

jk 

"just kidding"

you are stupid, jk

jk by Mikaela September 20, 2003

jk 

just kidding or just playing around

"Hey,I met bow wow yesterday and he told me he wanna go with me" JK

jk by Taylor November 24, 2003

jk 

Abbrieviation of "Just Kidding". Often mistaken as an abbrieviation of "Jokes", but this is still a widely accepted form of it.

"Lyke I was jk"
"Lolmfao, jk"

jk by AnnoyedBlackGuy July 13, 2006

jk 

joking, just kidding

Dan I hate you
Jk

jk by none of your beezwax April 17, 2003

jk 

i.m talk meaning "just kidding"

mostly used by people to insult others and still stay friends with them by two faced people.SOMETIMES used in a genuine way.

How it happens-
Cheerleaderbitch08:You looked like total shit last night!
Cheerleaderbitch08:JK!
You:Ahaha you r funny.

How it should happen-
Cheerleaderbitch08:You looked like total shit last night!
Cheerleaderbitch08:JK!
You:I will b jk'ing when I have my fist in ur face.
You:Ahaha jk!

jk by mandeebarrett January 9, 2009