crazy, half-baked, screwball, softheaded -- (foolish; totally unsound; "a crazy scheme"; "half-baked ideas"; "a screwball proposal without a prayer of working")
crazy -- (possessed by inordinate excitement; "the crowd went crazy"; "was crazy to try his new bicycle")
crazy -- (bizarre or fantastic; "had a crazy dream"; "wore a crazy hat")
crazy, wild, dotty, gaga -- (intensely enthusiastic about or preoccupied with; "crazy about cars and racing"; "he is potty about her")