Synonyms of asinine

1 Syllable
crass, daft
2 Syllables
tomfool, campy, screamer, silly, sillier, rioter, dafter, daftest, foolish, fatuous, witless, stupid, crasser, absurd, loopy, har-har, mindless, dippy, silliest, campiest, crassest, laughing
3 Syllables
inanest, nitwitted, softheaded, senseless, cretinous, inane, gelastic, idiotic, moronic, half-witted, squirrelly, laughable
4 Syllables
imbecilic, muddleheaded, imbecile, preposterous, derisory, harebrained, sophomoric, cockamamy