Synonyms of silliest

2 Syllables
pointless, childish, simple, fatuous, vacuous, witless, dizzy, stupid, balmy, flighty, empty, brainless, dippy, crazy
3 Syllables
frivolous, ignorant, meaningless, imprudent, nitwitted, sheepheaded, foolhardy, puerile, senseless, inane, idiotic, ludicrous, unwise
4 Syllables
illogical, irrational, empty-headed, featherbrained, muddle-headed, ridiculous, nonsensical, preposterous, immature, harebrained, asinine, simpleminded, inconsistent
5 Syllables
unreasonable, unintelligent, inappropriate, irresponsible