n. 25B6; noun
he couldn't pay his debts : BILL, account, dues, arrears, charges; financial obligation, outstanding payment, money owing; N. Amer. check; informal tab.
his debt to the author : INDEBTEDNESS, obligation; gratitude, appreciation, thanks.
25A0; in debt OWING MONEY, in arrears, behind with payments, overdrawn; insolvent, bankrupt, ruined; Brit. in liquidation; informal in the red, in Queer Street, on the rocks.
25A0; in someone's debt INDEBTED TO, beholden to, obliged to, duty-bound to, honour-bound to, obligated to; grateful, thankful, appreciative.