hear it again

: the rules governing the proper way to behave

Example sentence:
Grandma is a stickler for etiquette—don't talk with your mouth full, always say "please," no hats in the house—she's got rules for how to do everything!

Etymology:
In French, "etiquette" originally referred to a ticket or label attached to something, such as a bundle of documents. That French term gave rise to both "ticket" and "etiquette." English speakers weren't the only ones influenced by the French word. In the 1500s the Spanish royal court adopted the word "etiqueta" first to refer to documents describing proper courtly behavior and later to the behavior itself. When English speakers started using "etiquette" in the 1700s, its meaning expanded to include all sorts of rules for proper behavior required by society.