The act of getting a cat off your lap. This can be done in any number of ways, but the term usually refers to the use of a hearing aid turned up full volume as seen with Earl Pickles' cat, Muffin.
Muffin: (thinking to herself) Oh, Earl's lap, I'm going to jump up there and try to scratch him!
Earl: Stupid cat! Hey Clyde, get me my hearing aid!!!
Clyde: (yelling) What in the world for? Earl Pickles, are you crazy?
Earl: I'll show you what I mean. (turns up the hearing aid loud so it's squealing. Muffin jumps off his lap scared)
Clyde: (shocked) What on earth did you just do?
Earl: That, my friend, is the art of being Decatted!