A permanent mental condition that gives you thesub-average IQ of others. No. ADHD is not Retardation. Nor is Autism. If you ask a psychologist, they will tell you Autism and Mental Retardation are two different things. A lot of people who use "Retardation" as an insult can't even define it themselves.
A person who, no matter what the situation, will choose the worst course of action. They appear to be compulsively driven to make poor choices, stupid comments and even worse life decisions.
This person is often caught up in small details that have little if nothing to do with the larger picture, or situation at hand.
WTF dude! This is the third time today you've got your dick caught in the vacuum. You must be Obsessive Retarded.
To be comidicly-retarded is to be completely unaware of the joke at hand. As the great General Sam once said "some of you are comidicly-retarded. Pronunciation is rather simple: com-ee-dic-ly re-tar-ded.
This fucking asshole here. Doesn't even get the joke and he sits there bobbin' his stupid head along. He's comidicly-retarded.