insane kooky mad nuts nutty silly wacky ape berserk cuckoo lunatic potty psycho screwball barmy bats in the belfry batty bonkers cracked crazed daft delirious demented deranged dingy dippy erratic flaky flipped flipped out freaked out fruity idiotic mad as a March hare mad as a hatter maniacal mental moonstruck nutty as fruitcake of unsound mind out of one's mind out of one's tree out to lunch round the bend schizo screw loose screwy touched unbalanced unglued unhinged unzipped