This is the 1748th most frequent Russian word.
долг
"Долг" means "duty" or "debt" in English.
refers to a moral or societal obligation
Он выполнил свой долг перед Родиной.
He fulfilled his duty to the Motherland.
refers to a financial obligation or debt
Его долг в банке вырос за последний год.
His debt in the bank has increased over the last year.
refers to a moral duty or responsibility