Synonyms and related words :
amentia, arrested development, asininity, backwardness, battiness, blithering idiocy, brainlessness, buffoonery, clownishness, crackpottedness, crankiness, craziness, cretinism, daffiness, desipience, eccentricity, fatuity, fatuousness, folly, foolery, foolheadedness, foolishness, frivolity, frivolousness, giddiness, goofiness, half-wittedness, idiotism, imbecility, inanity, ineptitude, infantilism, insanity, lunacy, madness, mental defectiveness, mental deficiency, mental handicap, mental retardation, mindlessness, mongolianism, mongolism, mongoloid idiocy, moronism, moronity, niaiserie, nugacity, nuttiness, profound idiocy, queerness, retardation, retardment, sappiness, screwiness, senselessness, silliness, simple-wittedness, simplemindedness, simpleness, simplicity, stupidity, subnormality, thoughtlessness, triflingness, triviality, wackiness, weirdness, witlessness, zaniness, zanyism