Propriety /p(r)əˈprīədē / noun 

Definition:  Propriety has two similar but specific meanings:

1. Defining propriety requires a look at the word proper, or the state of being suitable for something, or being correct for a situation according to cultural norms. Hence, the first definition of propriety means being proper for the situation.

When taken together, proprieties, the plural form defines a polite society in terms of its manners and customs.

1. Propriety can also mean being scared of going against behavioral norms, particularly between two people in a romantic relationship.

When looked at as a group, propriety’s definitions describe following societal norms. Which definition applies depends on the context of the sentence someone uses it.

Etymology: Propriety’s origin is Latin as in proprietas, which means “appropriateness” and “ownership.” In Old French, proprieté means property.

In a Sentence

The Senator has an excellent sense of his constituent’s needs at the local level as he displays savvy political propriety, something that does him well in elections.

That couple over there making out is going against the city’s propriety regarding public indecency.

Despite her misgivings about the costume, she felt it would send anti-propriety energy throughout the entire festival.

Synonyms 

Decorum, Decency

Antonyms 

Impropriety, Indecency