KYS is an acronym for The killing of one's self / kill your self, typically said by call of duty gamers online.
KYS Toby, no one likes you
it is short for "Kill Your Self". Commenly used by Angry 6 year olds on call of duty
"You all SUCK, you should all KYS."
Stands for "Koala you slow"
Commonly used when describing airheads
"Dana kys"
"Dana you dense"
John hints to Dana the location of the treasure, but Dana doesn't get it.
John: "Gosh Dana kys"
troll: Keep Yourself Safe
salty: Kill YourSelf
*WARNING* the examples below are cringe-worthy, read at your own risk.
* unlikely scenario *
Person 1: KYS
Person 2: ?!
Person 1: keep yourself safe ;-)
Person 2: haha!
* likely scenario *
Person 1: *makes Person 2 mad*
Person 2: KYS kid!