Synonyms of foolish

1 Syllable

daft, mad, weak

2 Syllables

wacky, kooky, childish, barmier, schizoid, zaniest, goofy, madder, stupid, loony, batty, doltish, babyish, nerdy, buggy, daffy, buggies, witless, sheepish, ungrown, nutty, dopey, bum-steer, maddest, jerky, battiest, crazy, daffier, battier, dopier, silly, dafter, zanier, dottier, nuttiest, simple, lightweight, daftest, zany, whacko, absurd, wackiest, madcap, dippy, potty, nuttier, barmy, doting, dotty, pottier, fatuous, vacuous, swimmy, wackier, goofier, brainless, mindless, fooler

3 Syllables

stupidest, off-the-wall, imprudent, dupable, lightheaded, half-baked, ill-judged, incautious, senseless, short-sighted, cretinous, near-sighted, unwise, misguided, unthinking, light-minded, nonserious, lunatic, inanest, faked-out, inane, foolheaded, demented, half-witted, thick-headed, squirrelly, insane, fantastic, indiscreet, puerile, idiotic, gullible, frivolous, quixotic, nitwitted, unwiser, shortsighted, ludicrous, side-splitting, moronic, crackbrained, hare-brained

4 Syllables

irrational, ill-advised, preposterous, injudicious, overhasty, unsagacious, extravagant, harebrained, cockamamy, unsensible, unreasoning, disinformed, cockamamie, feebleminded, sophomoric, nonsensical, infatuated, babylike, asinine, unskeptical, lamebrained, imbecilic, featherbrained, ridiculous, bedlamite

5 Syllables

unreasonable, inadvisable, ill-considered, unadvisable, anencephalic, anencephalous, unintelligent, unreflective