noun

extremely stupid behaviour.

the idiocy of decimating yew forests

stupidity,folly,foolishness,foolhardiness,madness,insanity,lunacy,silliness,brainlessness,thoughtlessness,senselessness,lack of sense,indiscretion,irresponsibility,injudiciousness,imprudence,rashness,recklessness,ineptitude,inaneness,inanity,irrationality,illogicality,absurdity,nonsense,ludicrousness,ridiculousness,fatuousness,fatuity,asininity,pointlessness,meaninglessness,futility,fruitlessness,craziness,daftness