This is the 2991st most frequent Russian word.
долга
"Долга" is the genitive singular form of "долг," meaning "duty" or "debt."
Here, 'долг' refers to a financial or material obligation or loan.
Эта книга долг мне вернули вчера.
This book of my loan was returned to me yesterday.
In this sentence, 'долг' reflects a moral or ethical obligation or duty a person feels.
Выполнение долга всегда важно.
Fulfilling one's duty is always important.
Here, 'долг' denotes a figurative or moral debt associated with personal values.