Convention (noun)

1. A meeting or assembly of people who come together for a particular purpose.
2. A set of agreed, stipulated, or generally accepted rules, norms, standards, or criteria, often taking the form of a custom or tradition.
3. A general agreement among the members of a group or society.

Origin:

Late middle english: from old french, or from latin conventio(n-), from convenire "come together" (see convene).

Examples:

1. The convention was attended by representatives from many countries.
2. The company is following the conventions of the industry.
3. The convention for formatting this type of document.
4. The convention center.
5. The party convention.