IPA: /stjuːˈpɪdəti/
KK: /stjuːˈpɪdəti/
The quality or condition of lacking intelligence or good judgment.
His decision to invest in that failing company was a clear example of stupidity.
Stupidity → It is formed from "stupidus" (from Latin, meaning dull or foolish) and the suffix "-ity" (meaning the state or quality of). The word "stupidity" refers to the state of being dull or lacking intelligence.
Think of the Latin word for dullness ('stupidus') to remember that 'stupidity' means the quality of being dull or foolish.