Interest debt refers to a situation where an individual or entity owes money, but also has to pay interest on that borrowed amount. This means that not only do they have to repay the principal sum, but they must also make regular payments towards the accumulated interest charges. Interest debt can be accrued through various sources such as loans, credit cards or other types of financing. The longer it takes to repay the original amount, the more interest will be added to the total balance, making it harder and more expensive to eliminate completely.