stupidness

the quality or state of lacking intelligence or quickness of mind I'm not sure if he leaves his front door unlocked from carelessness or just plain stupidness Synonyms boneheadedness, brainlessness, denseness, density, dim-wittedness, doltishness, dopiness, dorkiness, dullness (also dulness), dumbness, fatuity, foolishness, gormlessness [chiefly British], mindlessness, oafishness, obtuseness, senselessness, simpleness, slowness, stupidity, thickness, vacuity, weak-mindedness, witlessnessRelated Words feeblemindedness, simplemindedness; absurdity, asininity, balminess, craziness, daftness, dippiness, dottiness, fatuousness, folly, idiocy, inaneness, inanity, insanity, lunacy, madness, nincompoopery, nonsensicalness, nuttiness, preposterousness, silliness, simplicity, wackiness, zaniness; fallacy, irrationality, unreasonableness; mental deficiency, mental retardationNear Antonyms acumen, alertness, astuteness, discernment, insight, judgment (or judgement), perception, percipience, perspicacity; sagacity, sageness, sapience, wisdom, wit; logicality, logicalness, rationality, rationalness, reasonableness, soundness, validityAntonyms braininess, brightness, brilliance, cleverness, intelligence, keenness, quickness, quick-wittedness, sharpness, smartness