the.com/propriety

means Behavior and manners that conform to what's considered socially correct, polite, or morally acceptable.

from From French 'propriété', which splintered off the Latin 'proprietas' (ownership, a characteristic quality) — itself from 'proprius', meaning 'one's own, particular to oneself'. The same Latin root gives us 'property' and 'proper'. Somewhere along the way the sense narrowed: what was 'proper' to a person — fitting, suitable, belonging rightly to them — curdled into what was socially owed to everyone else. Owning yourself became owing others good behavior.