Retard.
n. Offensive Slang
1. Used as a disparaging term for a mentally retarded person.
2. A person considered to be foolish or socially inept.
Often used in the wrong context in World Of Warcraft.
I thought I would clear that up for those of you who throw this word around freely, as I seem to be seeing it more and more commonly these days.
So, think twice before calling someone a retard because in actual fact, it may be you who is the social inept one OR foolish one.
*Edited for the sake of the pedantic*