treaty
n
1 [C] formal agreement between two or more countries (国家之间的)条约, 协定
the Treaty of Rome 罗马条约
make/sign a `peace treaty with a neighbouring country 与邻国签订和平条约.
2 [U] formal agreement between people, esp for the purchase of property (人与人之间的)协议, 协商
sell a house by private treaty, ie instead of by public auction, etc 私下商议出售房子(不经公开拍卖等方式).