CKO

Cool kids only.

J: *writes CKO on paper*
K: What does that mean?
J: Cool kids only

CKO

Crunk knock-out

Sorry fam, I can’t go out tonight. Already snagged the 6er of hamms and planned a CKO for 2n.

CKO

Short for Cider knockout, when someone falls asleep at an inconvenient time after drinking lots of Cider.

I was watching that TV series last night when I had a CKO, so I hope it's repeated soon!