What someone is when they fuck up in a stupendously amazing fashion or are just incredibly stupid in general. Must be used with the following inflection:
"You're an absolute FUCKing walnut!"
-After Dave finished his explanation why whites and blacks are different species-
"Dave, you're an absolute FUCKing walnut!"
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.