Synonyms of preposterous

1 Syllable

mad, droll, thick, wild

2 Syllables

wacky, off-base, schizoid, monstrous, unapt, madder, stupid, moonstruck, cockeyed, loopy, noway, tomfool, campy, sillier, maddest, sappy, shocking, droller, no-go, no-way, laughing, crazy, screamer, silly, rioter, loco, whacko, absurd, wackiest, dippy, potty, silliest, laffer, sappier, foolish, pottier, camer, wackier, far-out, har-har, campiest

3 Syllables

fanciful, extreme, off-the-wall, outrageous, farcical, unfitting, teratoid, lunatic, senseless, unusual, improper, grotesque, gelastic, far-fetched, foolheaded, outlandish, unheard-of, farfetched, insane, softheaded, fantastic, uncurbed, miscreated, egregious, ludicrous, side-splitting, hare-brained, laughable

4 Syllables

irrational, unconforming, out-of-place, out-of-season, unbefitting, extravagant, incredible, harebrained, unnatural, muddleheaded, unreasoning, cockamamie, derisory, proscriptive, unworkable, unrenowned, excessive, schizophrenic, unthinkable, nonsensical, exorbitant, asinine, illogical, imbecilic, impossible, ridiculous, untempered

5 Syllables

unreasonable, unconscionable, unmeasurable, inapposite, inordinate, irrealizable, unrealizable, unbelievable, overindulgent, prohibitive, exaggerated

6 Syllables

counterintuitive