accession to a treaty是什么意思？

accession to a treaty

加入条约；加盟

accession

n. 增加，就职，增加物，（对同盟、国际条约等的）正式加入；

例句
...the 50th anniversary of the Queen's accession to the throne.
女王登基50周年庆典

to

prep. 向，朝着，到，关于，属于；adv. 朝一个方向的，到某种状态，关闭；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

treaty

n. 条约，协议，协商，谈判；

例句
Delegates signed a treaty to reduce the armouries of conventional weapons in Europe.
各代表签署了协议以减少欧洲的常规武器装备。