Synonyms of silly

1 Syllable

schtick, daft, schmuck, gump, fool, fools, schmoes, schmo

2 Syllables

wacky, childish, trifling, apest, stupid, loony, batty, flighty, slushy, babyish, loopy, sobby, empty, funnier, schmaltzy, boffo, funny, tomfool, pointless, scatty, crazier, turkey, witless, sheepish, ungrown, dopey, craziest, flightier, sappy, clocker, ninnies, battiest, crazy, battier, dopier, dafter, dingdong, cuckoo, quick-fix, simple, daftest, dizzy, aper, ninny, soupy, balmy, absurd, wackiest, softhead, dippy, funniest, potty, loonier, doting, sappier, mooncalf, foolish, pottier, fatuous, vacuous, wackier, goofus, flightiest, brainless, mindless

3 Syllables

off-the-wall, meaningless, imprudent, foolhardy, half-baked, senseless, cretinous, unwise, starry-eyed, tear-jerking, inanest, inane, foolheaded, slaphappy, half-witted, squirrelly, comical, ignorant, smattery, softheaded, puerile, idiotic, gullible, frivolous, birdbrained, nitwitted, sheepheaded, unwiser, fool-headed, ludicrous, knee-slapper, hare-brained

4 Syllables

irrational, preposterous, extravagant, unrealistic, rosewater, harebrained, nonrealistic, scatterbrained, cockamamy, addlebrained, unreasoning, sentimental, pixilated, cockamamie, sidesplitting, simpleminded, addleheaded, nongermane, nonsensical, infatuated, babylike, immature, rattlebrained, asinine, unskeptical, addlepated, illogical, lamebrained, imbecilic, empty-headed, featherbrained, muddle-headed, ridiculous, superficial, inconsistent

5 Syllables

unreasonable, inappropriate, irresponsible, ivory-tower, anencephalic, anencephalous, unintelligent, unreflective

6 Syllables

one-dimensional