Definitions by The 8th best man.

fuck whistle

Idiot, moron, one who lacks the most basic common sense to make correct decisions,see ass clown.

That fuck whistle doesn't know his ass from a hole in the ground!

adjective; Small, of little or no consequence compared to other objects,ideas or sentiment.

He blew a grand in Atlantic City? That's mice nuts compared to what he dropped in Vegas!