a shortened version of the word "okay," usually used online or by teenage girls that are trying to piss off their parents by cutting every sentence they say (usually asking said teenage girl to do something she doesn't want to do) short. can also effectively end a conversation.
Mom: honey, i need you to take out the tra-
Mom: and i also need you to clean your roo-
Mom: alright, now i'm pissed. no facebook for a mon-
Mom: is that all you can say?
Jenny: no, i can also say "shut up, kay?"