treaty

noun | trea·ty

1. : the action of treating and especially of negotiating

   a : private treaty

   b : a contract in writing between two or more political authorities (as states or sovereigns) formally signed by representatives duly authorized and usually ratified by the lawmaking authority of the state the President…shall have power, by and with the advice and consent of the Senate, to make treaties —U.S. Constitution art. II — compare executive agreement

3. : a document embodying a negotiated agreement or contract

4. : an agreement or contract (as between companies) providing for treaty reinsurance