Being of complete stupidity, ignorance, and total cluelessness. Typically used among close friends.
Jake: "Hey look, Christmas is on a Sunday this year"
Charles: "Christmas is always on a Sunday"
Jake: "No it's not! You are RARDED!
The same as calling someone “retarted” but now most (including actual retarted people) won’t understand what you’re saying meaning you can’t publicly call someone that without getting in trouble.
Hey spook! You acting rarded nigga.
Its a typo of retarded. Just a replacement word for retarded.