Synonyms and related words:
apish, asinine, batty, befooled, beguiled, besotted, brainless, buffoonish, cockeyed, crazy, credulous, daffy, daft, dazed, dizzy, doting, dumb, fatuitous, fatuous, flaky, fond, fool, foolish, fuddled, futile, gaga, goofy, gulled, idiotic, imbecile, inane, inept, infatuated, insane, kooky, loony, mad, maudlin, moronic, nutty, sappy, screwy, senseless, sentimental, silly, stupid, thoughtless, wacky, wet, witless