dullness of mind, absurdity, apathy, asininity, battiness, brainlessness, doltishness, fatuity, fatuousness, feeble-mindedness, idiocy, ignorance, imbecility, imprudence, incapacity, ineptitude, injudiciousness, insensibility, lunacy, nitwittedness, nonsense, obtuseness, puerility, shallowness, silliness, simplicity, slowness, slowness, sluggishness, stolidity, stupefaction, stupidness, stupor, thick-headedness, weak-mindedness, weakness...