vacuous, vapid, obtuse, doltish, dozy, cretinous, wooden-headed, daft, muttonheaded

exactly how i feel today...

stupid |ˈst(y)oōpid| adjective ( -pider, -pidest) lacking intelligence or common sense : I was stupid enough to think she was perfect.
• dazed and unable to think clearly : apprehension was numbing her brain and making her stupid.
• informal used to express exasperation or boredom : she told him to stop messing with his stupid painting. noun informal a stupid person (often used as a term of address) : you're not a coward, stupid!

DERIVATIVES stupidity |st(y)oōˈpiditē| noun stupidly adverb ORIGIN mid 16th cent.: from French stupide or Latin stupidus, from stupere ‘be amazed or stunned.’

Thesaurus
stupid adjective
1 they're rather stupid unintelligent, ignorant, dense, foolish, dull-witted, slow, simpleminded, vacuous, vapid, idiotic, imbecilic, imbecile, obtuse, doltish; informal thick, dim, dimwitted, dumb, dopey, dozy, moronic, cretinous, pea-brained, halfwitted, soft in the head, brain-dead, boneheaded, thickheaded, wooden-headed, muttonheaded, daft. antonym intelligent.
2 that was a really stupid thing to do foolish, silly, unintelligent, idiotic, scatterbrained, nonsensical, senseless, unthinking, ill-advised, ill-considered, unwise, injudicious; inane, absurd, ludicrous, ridiculous, laughable, risible, fatuous, asinine, mad, insane, lunatic; informal crazy, dopey, cracked, half-baked, dimwitted, cockeyed, harebrained, lamebrained, nutty, batty, cuckoo, loony, loopy. antonym sensible.
3 he drank himself stupid into a stupor, into a daze, into oblivion; stupefied, dazed, unconscious. antonym alert.

thanks to the cool apple dictionary for the above information.