1. Commonly coming from somebody who lives in Boston, this is the stupidest possible way to call something retarded or "not cool." Put simply it's a way to call something really dumb.
2. A phrase that connotes, "Hi. I'm from Southy and I'm a piece of shit. Please beat my ass."
Alternate(And in this case the proper) Spelling: Wicked Retahded.
"Mayn dood. That shit is wicked retarded!"