An abbreviation for 'Okay, you.' Used for when you're with little kids, or a drunk person.
"K'you, go upstairs and clean yourself up." you might say
"buh i don feel guud..." & then they'd barf all over you. hahah.
Shortened edition of "Thank you", often used by those straining to put themselves "Above" everyone else, such as Rockstars, often delivered prior to anything that would warrant the aforementioned thank you.
Lead Singer to Crowd, prior to applause: "K'you"