accepted social custom or practice, or a specific form or use

a generally agreed principle or practice

an agreement between states that regulates matters affecting all of them

a compact between opposing military commanders, esp one concerning prisoner exchange or armistice

an assembly of people met for a common purpose; a conference

a meeting of the delegates of a US political party for the purpose of formulating policies and selecting candidates for office

an established artistic technique or practice

an agreed system of bidding or playing that conveys information between partners in bridge or other card games