agreement、contract、treaty、convention、bargain、understanding与accord这些名词均含“协定、协议、契约、合同”之意。
agreement ：普通用词，含义最确定，泛指个人、团体或国家之间取得一致而达成的任何协议、协定或合同、契约等，可以是口头的，也可以是书面的。
- An agreement was finally reached between management and employees.
劳资双方终于达成了协议。 - They had made a verbal agreement to sell.
他们达成了口头售货协定。
contract ：侧重指双方或多方订立的具有法律效力的正式的书面合同或契约。
- to enter into/make/sign a contract with the supplier
与供应商签订合同
（拓展学习：熟词僻义 | 当 contract 遇上新冠肺炎）
treaty ：指国家之间经外交谈判后依照国际法签订的正式条约。
- the Treaty of Rome, which established the European Community
建立了欧洲共同体的《罗马条约》
convention ：比 treaty 更专门化，但不及 treaty 正式。也可指国家之间就有关事情签订的条约。
- the Geneva convention
日内瓦公约 - the United Nations convention on the rights of the child
联合国儿童权利公约
bargain ：通常指商业交往中的购销合同。
- We shall be able to tell whether you've kept your side of the bargain.
我方应能知道你方是否遵守了协议。 - The treaty was based on a bargain between the French and German governments.
这个条约是以法国和德国政府之间的一个协议为基础的。
understanding ：指不具约束力的非正式的协议。
- We finally came to an understanding about what hours we would work.
我们最终就工作时间问题取得了一致意见。 - We have this understanding that nobody talks about work over lunch.
我们有个默契：吃午饭时谁也不许谈工作。
accord ：多指国际间的正式协议。
- The two sides signed a peace accord last July.
在刚过去的七月，双方签订了和平条约。
