Englishfatuous
adjective
she was irritated by a fatuous question:
silly, foolish, stupid, inane, nonsensical, childish, puerile, infantile, idiotic, brainless, mindless, vacuous, imbecilic, asinine, witless, empty-headed, hare-brained;
pointless, senseless;
ridiculous, ludicrous, absurd, preposterous, laughable, risible;
informal moronic, cretinous, dumb;
British, informal daft, gormless.
▷antonyms intelligent, sensible.
fatuous Oxford Dictionary of English