1. when you ask a person to do something in the form of a request and the person pretends like they don't understand. Then they repeat the action which you wish them to perform back a to you thus becoming your retarded echo.
2. a human parrot who repeats what someone says as if they cannot think of something interesting to say themselves.
1. Sally: "Hey Bob, could you take out the trash?"
Bob: "Take out the trash?"
Sally: "There goes that retarded echo again..."
2. Bully 1: "Shut up dumbfuck!"
Bully 2: "Yeah, Shut up dumbfuck!"