join up

Từ điển Oxford Advanced Learner 8th

▪ I. ˌjoin ˈup derived
(BrE)to become a member of the armed forces
Syn: ↑enlist
•Her grandfather joined up in 1914.
Main entry: ↑join_derived
 
▪ II. ˌjoin ˈup (with sb) derived
to combine with sb else to do sth
•We'll join up with the other groups later.
Main entry: ↑join_derived