owe
Synonym discussion
Sense: verb/1
Owe is the normal verb when you still need to pay money, return something, or give something back: You owe the bank two hundred dollars. Be in debt describes the situation more generally and often suggests a larger money problem, not just one unpaid item. Be indebted is more formal and appears often in writing or business English. Have outstanding is common for unpaid bills, fees, or balances in notices and account records. Repay is different because it describes the action of paying back, not the state before payment. Compare: I owe Sara ten dollars. The shop is deeply in debt. The client still has two invoices outstanding.
Etymology
Owe comes from Old English agan, a verb that first meant to own or possess. From the idea of having something in your possession, English later developed the sense of having something due to another person. That is why modern owe can describe money that must be paid, thanks that should be given, or success that is traced back to a cause.