noun
Etymology: Middle English, from Middle French or Latin; Middle French, from Latin convention-, conventio, from convenire
Date: 15th century
1. agreement , contract , an agreement between states for regulation of matters affecting all of them, a compact between opposing commanders especially concerning prisoner exchange or armistice, a general agreement about basic principles or procedures,
2. the summoning or convening of an assembly, an assembly of persons met for a common purpose, the usually state or national organization of a religious denomination,
3. usage or custom especially in social matters, a rule of conduct or behavior, a practice in bidding or playing that conveys information between partners in a card game (as bridge), an established technique, practice, or device (as in literature or the theater)