"chris Man grow up you're 45, and you're not even bloody irish!"
1. sound noting confusion or disbelief
2. Posing the question, "what is going on."
Etymology: Likely to have come from Scooby-Doo often reacting to the order to go search for ghosts with Shaggy. Picked up in the late 90s.
Guy: Aru??! He what!?
Bill: Come here, Joe. We need your help.