IPA: /pərˈvɜːrsɪti/
KK: /pərˈvɜrsɪti/
A quality or state of behaving in a way that is contrary to what is expected or desired, often in a stubborn or unreasonable manner.
His perversity made it difficult for him to maintain friendships.
**Perversity** → It is formed from "per-" (meaning through or thoroughly) and "vertere" (meaning to turn). The word describes a state of being turned away from what is right or good, hence a moral deviation.
Think of something being 'thoroughly turned' ('per-') in the wrong direction ('vertere') — that's why perversity means a moral deviation.
No commonly confused words.