convention

Concise Oxford English Dictionary © 2008 Oxford University Press:
convention/kənˈvenʃn/

▶noun

• 1 a way in which something is usually done.

  ■ socially acceptable behaviour.

• 2 an agreement between states, especially one less formal than a treaty.

• 3 a large meeting, especially of members of a political party or a profession.

  ■ N. Amer. an assembly of the delegates of a political party to select candidates for office.

  ■ a body set up by agreement to deal with a particular issue.

  ■ historical a meeting of Parliament without a summons from the sovereign.

• 4 Bridge a bid or system of bidding by which the bidder tries to convey specific information about the hand to their partner.

– origin ME: via OFr. from L. conventio(n-) ‘meeting, covenant’, from convenire (see convene).