reunion

n. 团圆,重聚

We hold an annual reunion of former students of the college.

我们每年举行一次大学校友联欢会。

Thanks invitation however regret unable join owing business pressure hoping reunion before christmas best regard.

谢谢邀请，很抱歉，由于商务繁忙不能前往。希望在圣诞节前能得到一叙。祝好。