silly

[1]

fool , nincompoop , idiot , dunce , ninny , halfwit , simpleton , numskull/numbskull , dim-wit , booby , dolt , jackass , twit , dolt , blockhead , bonehead , nitwit , ignoramus , clod , (US) thimble-wit , (Colloq) dope , dummy , knuckle-head , goose , drip , silly billy , (Brit) clot , (Slang) (US/Canadian) jerk , nerd

adj.

[1]	senseless , nonsensical , absurd , ridiculous , ludicrous , laughable , risible , asinine , inane , preposterous , idiotic , childish , puerile , foolish , foolhardy , irresponsible , unreasonable , illogical , irrational , pointless , fatuous , stupid , unwise , imbecilic , crazy , mad , insane
[2]	stunned , cockamamie , cockamamy , stupefied , daze , goofy , sappy , giddy , dizzy , wacky , whacky , muzzy , benumbed , zany
[3]	airheaded , dizzy , empty-headed , featherbrained , giddy , light-headed , lightheaded
[4]	pathetic , ridiculous
[5]	punch-drunk , slaphappy