Derped (v.) To derp or have the action of derp be used upon you.
Shannon really derped when she fell face first on her skateboard.
Michael was derped when Christina tried to explain quantum physics to him.
Being derped is being karate chopped by Derpy Hooves. Since she is a derp and a screw up, she may karate chop you to make you screw up.
Person 1: Dude, why'd you drop your phone?
Person 2: I got derped.