utterly senseless or foolish behavior; a stupid or foolish act, statement, etc.

Psychology . the state of being an idiot.

noun

brains , intelligence

noun

asininity , cretinism , derangement , fatuity , fatuousness , foolishness , imbecility , inanity , insanity , insipidity , lunacy , madness , senselessness , tomfoolery , absurdity , folly , foolery , nonsense , preposterousness , silliness , zaniness , balderdash , blather , bunkum , claptrap , drivel , garbage , piffle , poppycock , rigmarole , rubbish , trash , twaddle