What does propriety mean?

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From our dictionary:

pro•pri•e•ty

Pronunciation: (pru-prI'i-tE), [key]
n.,
pl. -ties.

1. conformity to established standards of good or proper behavior or manners.
2. appropriateness to the purpose or circumstances; suitability.
3. rightness or justness.
4. the proprieties,the conventional standards of proper behavior; manners: to observe the proprieties.
5. Obs.a property.
6. Obs.a peculiarity or characteristic of something.