expression, godan verb (-su)
pay back a debt; repay a loan
Literal financial repayment of borrowed money or a favor.
彼に借りたお金をやっと借りを返せた。
I finally managed to pay back the money I borrowed from him.
expression, godan verb (-su)
get revenge; settle a score; get back at someone
Idiomatic use for retaliating or evening a score, often in a personal or dramatic context.
いつかこの借りを返してやる。
I'll get back at you for this someday.