noun
plural debts
[count] :an amount of money that you owe to a person, bank, company, etc.
[noncount] :the state of owing money to someone or something
[count] :the fact that you have been influenced or helped by someone or something - usually singular
debt to society
used in phrases like pay your debt to society to refer to being punished for committing a crime
in someone's debt
If you are in someone's debt, you are very thankful for something that someone has done for you.
owe a debt of gratitude/thanks to
to have a good reason to be very grateful to (someone)