Noah Webster's New International Dictionary of the English Language

1. (n.) Appropriateness; suitableness to established standards and principles, rules, or customs; fitness; appropriateness; as, propriety of behavior, language, manners, etc.

2. (n.) Individual right to hold property; ownership by personal title; property.

3. (n.) That which is proper or peculiar; an inherent property or quality; peculiarity.