join up有团结的意思吗

有的，
join up的意思是 v.参军,联合起来

join up
参军, 入伍
On leaving college, my brother joined up.
我的兄弟大学毕业后参军了。

(使)合拢; (使)联合
I'm glad to see that the edges of the wound are joining up nicely.
我高兴地看到伤口的边缘正在很好地愈合。