pay something back to somebody

Từ điển Oxford Advanced Learner 8th

ˌpay sb ˈback (sth) | ˌpay sthˈback (to sb) derived
to return money that you borrowed from sb
Syn: ↑repay
•I'll pay you back next week.
•You can pay back the loan over a period of three years.
•Did he ever pay you back that $100 he owes you?
Main entry: ↑pay_derived