hang back

Từ điển Oxford Advanced Learner 8th

▪ I. ˌhang ˈback derived
to remain in a place after all the other people have left
Main entry: ↑hang_derived
 
▪ II. ˌhang ˈback (from sth) derived
to hesitate because you are nervous about doing or saying sth
• I was sure she knew the answer but for some reason she hung back.
Main entry: ↑hang_derived