The photographer has acknowledged a/his 'debt' to Andy Warhol. [=the photographer has said that his work was influenced by the photographs made by Andy Warhol]
banks with millions of dollars of 'bad debt' [=banks that have loaned millions of dollars that will not be repaid]
She's finally paid off her mortgage 'debt'. [=the money that she owed the bank to pay for her house]
(..) Boromir died to save us... ...my kinsman and me. - He fell defending us from many foes. - Pippin. I offer you my service, such as it is... ...in payment of this debt. This is my first command to you. How did you escape and my son did not... ...so mighty a man as he was? The mightiest man (..)2003 The Lord of the Rings: The Return of the King