What is the meaning of Convention?

A meeting or gathering.

A formal deliberative assembly of mandated delegates.

The convening of a formal meeting.

A formal agreement, contract, rule, or pact.

A treaty or supplement to such.

A practice or procedure widely observed in a group, especially to facilitate social interaction; a custom.

convention, agreement

convention (formal meeting)

convention (conventionally standardised choice)

Source: wiktionary.org