The sound Sylvester Stallone emits from his mouth when diving away, avoiding, or jumping from a fatal explosion; or if Stallone is absent: a Stallone type character, actor (most likely Arnold Schwarzenegger), or animal (most likely a dog)
(Some guy) Look out!
(Stallone) What?
*Looks at ticking time bomb just about to hit one second.*
(Stallone) Rooooooooo!
*Dives away from explosion.*
Being an instance in which a usually comedic situation is set up purely for the reaction of confusing/going over the head of a victim(s)
Bastardised form of the word "Whoosh" used to symbolise the conversation flying over the head of the poor fool involved.
Origins:racist-from the stereotyped Oriental trait of confusing R's with other letters