Crazy

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

foolish silly absurd ridiculous nonsensical strange weird bizarre outrageous idiotic inane ludicrous peculiar goofy insane fatuous balmy loony cockeyed eccentric half-baked harebrained impracticable unworkable short-sighted irresponsible imprudent ill-conceived quixotic puerile derisory beyond all reason out of all reason senseless foolhardy inappropriate