stupid

Synonyms: brainless dazed deficient dense dim doltish dopey dull dumb dummy foolish futile gullible half-baked half-witted idiotic illadvised imbecilic inane indiscreet insensate irrelevant laughable loser ludicrous meaningless mindless moronic naive nonsensical obtuse out to lunch pointless puerile rash senseless shortsighted simple simpleminded slow sluggish stolid stupefied thick thickheaded trivial unintelligent unthinking witless

Antonyms: cognizant intelligent responsible smart