Stupor; astonishment; stupefaction.

The quality or state of being stupid; extreme dullness of perception or understanding; insensibility; sluggishness.

a poor ability to understand or to profit from experience

Stupidity is the quality or condition of being stupid, or lacking intelligence, as opposed to being merely ignorant or uneducated. This quality can be attributed to both an individual (e.g. Penny Person is stupid) or a person's actions, words or beliefs (e.g., Penny Person's policies are stupid).

a stupid mistake