dullness of mind
● Silliness
● Lunacy
● Apathy
● Ignorance
● Nonsense
● Idiocy
● Absurdity
● Simplicity
● Stupor
● Stolidity
● Fatuity
● Weakness
● Sluggishness
● Ineptitude
● Insensibility
● Imprudence
● Incapacity
● Stupefaction
● Slowness
● Imbecility
● Fatuousness
● Obtuseness
● Asininity
● Puerility
● Injudiciousness
● Shallowness
● Battiness
● Brainlessness
● Doltishness
● Feeble-mindedness
● Nitwittedness
● Stupidness
● Weak-mindedness
● Canniness
● Judgment
● Sense
● Intelligence
● Shrewdness
● Acumen
● Wisdom
● Thickheadedness