stupidity

[1]

fatuity , obtuseness , dullness , denseness , lumpishness , doltishness , simplicity , simple-mindedness , imbecility , cretinism , feeble-mindedness , weak-mindedness , stolidity , dull-wittedness , dimness , dim-wittedness , halfwittedness , thick-wittedness , slow-wittedness , thimble-wittedness , witlessness , brainlessness , mindlessness , empty-headedness , feather-headedness , rattle-headedness , boneheadedness

[2]

foolishness , betise , folly , folly , asininity , foolishness , imbecility , craziness , insanity , madness , absurdity , absurdness , inanity , idiocy , ridiculousness , risibility , ludicrousness , nonsense , senselessness , bootlessness , irresponsibility , irrationality , foolhardiness