convention

(noun) a large formal assembly. Example: "Political convention."

(noun) something regarded as a normative example. Synonyms: normal, pattern, rule, formula. Examples: "The convention of not naming the main character." "Violence is the rule not the exception." "His formula for impressing visitors."

(noun) (diplomacy) an international agreement.

(noun) orthodoxy as a consequence of being conventional. Synonyms: conventionality, conventionalism.

(noun) the act of convening. Synonyms: convening.