A Onuvanja, it is a loan that I was meaning, but more like a specific type of loan. My dictionary brought up the word “iasacht”, and since there are quite a few things that I could count as “debts” I think “na fiacha” might be too general, but thank you for the input. What about “iasacht” is not quite right there?
I think “iasacht” refers more to the action of lending/borrowing than the thing that is lent/borrowed. It occurs often in combination with the preposition “ar”, e.g. “rud a fháil ar iasacht” – “to borrow something” (to get something by means of borrowing). In other cases, it is used in the genitive and functions as a adjective/qualifier, meaning “borrowed; foreign; strange”, e.g. “duine iasachta” – “foreigner”.