Balloon, absurd, footling, dazed, airhead, and alec are all synonyms for silly. Sensible and rational are antonyms of silly. And here are 192 another word for silly.
Absurd, birdbrained, blockheaded, boneheaded, brain-dead, brainless, childish, chowderheaded, chuckleheaded, crazy, cretinous, daft, damfool, dappy, dim-witted, dim, dippy, divvy, dof, doltish, dopey, dotish, dotty, dumb-ass, dunderheaded, empty-headed, erratic, farcical, fat-headed, fatuous, feather-brained, flighty, foolhardy, foolish, frivolous, giddy, glaikit, half-baked, half-witted, hare-brained, idiotic, ill-considered, illogical, imbecile, imbecilic, immature, imprudent, inadvisable, inane, inappropriate, injudicious, irrational, irresponsible, lamebrained, laughable, loopy, ludicrous, mad, mindless, misguided, muttonheaded, pea-brained, pie-faced, pinheaded, preposterous, puerile, rash, reckless, ridiculous, risible, scatterbrained, scatty, screwy, senseless, slow-witted, soft, stupid, thick, thickheaded, thoughtless, tomfool, unintelligent, unreasonable, unstable, unwise, weak-minded, witless, wooden-headed, and asinine are all synonyms for silly.
Footling, frivolous, inconsequential, insignificant, minor, niggling, of little account, petty, piddling, piffling, slight, small, trifling, trivial, unimportant, and small-bore are all another word for silly.
Dazed, dopey, groggy, insensible, into a daze, into a stupor, into oblivion, into senselessness, numb, senseless, stunned, stupefied, stupid, unconscious, and muzzy are all synonyms for silly.
Airhead, alec, balloon, berk, birdbrain, bogan, bonehead, boob, boofhead, bozo, chucklehead, chump, clod, clodpole, clot, coot, dill, dimwit, dingleberry, dip, donkey, dope, drongo, dumbass, dumbhead, dumbo, dummy, dunce, fathead, galah, galoot, goof, goofball, goofus, goon, gowk, jackass, knucklehead, lamebrain, lummox, mompara, muttonhead, nincompoop, ninny, nit, nitwit, noddy, nong, noodle, nyaff, palooka, pea-brain, pinhead, poon, poop, pudding-head, scatterbrain, schlepper, silly billy, simp, simpleton, spoony, spud, stupe, sumph, thickhead, twerp, twit, wooden-head, yo-yo, and mooncalf are all another word for silly.
Silly synonym page has a variety of synonyms that differ in length. 5 synonyms with 3 letters and 23 synonyms with 4, and 7 letters. 27 synonyms with 5 letters and 18 synonyms with 6 letters.
19 synonyms with 8 letters and 25 synonyms with 9 letters. 12 synonyms with 10 letters and 16 synonyms with 11 letters. 7 synonyms with 12, and 13 letters and 2 synonyms with 14, and 15 letters. 1 synonym with 17 letters. For a total of 187 another word for silly.
That was a really silly mistake.
She wore a silly hat today.
Stop being silly and focus now.
He told a very silly joke.