n.

1. 再联合；再会合[U][S1]
   He was instrumental in the reunion of the two parties.

   他对两党再次联合起到了促进作用。

2. （亲友等的）团聚，重聚；重聚联欢会[C]
   Our family has a yearly reunion.

   我们每年合家团聚一次。

n.

1. the process or an instance of reuniting.
2. a social gathering attended by members of a group of people who have not seen each other for some time.