foolishShe was really foolish to quit her job like that.
sillyIt was silly of you to go out in the sun without a hat.
crazyYou'd be absolutely crazy to marry that man.
dumbmainlyUSinformalShe was terrified of asking dumb questions.
unintelligentThey are not unintelligent, just ill-informed.
absurdWhat an absurd thing to say!
ridiculousDo I look ridiculous in this hat?
ludicrousI think giving young children such expensive jewellery is a ludicrous idea.
idioticWhat are you doing with that idiotic jerk?
out of your mindYou must be out of your mind spending so much money on a car.
ignorantSome ignorant person has parked across our drive.