Ghost
When on a IM someone types so that it says "'Whoever' Is Typing" telling you that you will soon have a message, but then the person deletes what they were going to say and so this message disappears. This is called a ghost.
JM says: did you go out last night? *Last message recieved: 21:22* *JK is typing a message* *Last message recieved: 21:22* JM says: Ghost
By J.D.C.M.