Used to describe a person without street smarts; i.e. lacking the common sense required to deal with the potential dangers of real life outside of school.
1: Sure, he gets straight A's and all, but he's extremely streetarded.
2: Damn.
1. Describing an action, person, or circumstance that is so ridiculous and idiotic that neither "stupid" nor "retarded" can rightfully describe it on their own.
Obama: I know our national debt is in the trillians but let's spend 800 billion more imaginary dollars to jump start the economy.