imbecility β an instance or point of weakness; feebleness; incapability.
insipidity β without distinctive, interesting, or stimulating qualities; vapid: an insipid personality.
tomfoolery β foolish or silly behavior; tomfoolishness.
absurdity β the quality or state of being absurd; nonsense
apathy β You can use apathy to talk about someone's state of mind if you are criticizing them because they do not seem to be interested in or enthusiastic about anything.
idiocy β utterly senseless or foolish behavior; a stupid or foolish act, statement, etc.: All this talk of zombies coming to attack us is pure idiocy.
ignorance β the state or fact of being ignorant; lack of knowledge, learning, information, etc.
nonsense β words or language having little or no sense or meaning.
imprudence β not prudent; lacking discretion; incautious; rash.
incapacity β lack of ability, qualification, or strength; incapability.
ineptitude β quality or condition of being inept.
injudicious β not judicious; showing lack of judgment; unwise; imprudent; indiscreet: an injudicious decision.
insensibility β incapable of feeling or perceiving; deprived of sensation; unconscious, as a person after a violent blow.
obtuseness β not quick or alert in perception, feeling, or intellect; not sensitive or observant; dull.
puerility β the state or quality of being a child.
shallowness β of little depth; not deep: shallow water.
simplicity β the state, quality, or an instance of being simple.
slowness β moving or proceeding with little or less than usual speed or velocity: a slow train.
sluggish β indisposed to action or exertion; lacking in energy; lazy; indolent: a sluggish disposition.
stolidity β not easily stirred or moved mentally; unemotional; impassive.
stupefaction β the state of being stupefied; stupor.
stupor β suspension or great diminution of sensibility, as in disease or as caused by narcotics, intoxicants, etc.: He lay there in a drunken stupor.
weakness β the state or quality of being weak; lack of strength, firmness, vigor, or the like; feebleness.
battiness β the characteristic of being batty; craziness; insanity; eccentricity
brainless β If you describe someone or something as brainless, you mean that you think they are stupid.
doltishness β The characteristic of being doltish.