A revolving account is an account created by a lender to represent debts where the outstanding balance does not have to be paid in full every month by the borrower to the lender. The borrower may be required to make a minimum payment, based on the balance amount. However, the borrower normally has the discretion to pay the lender any amount between the minimum payment and the full balance. If the balance is not paid in full by the end of a monthly billing period, the remaining balance will roll over or "revolve" into the next month. Interest will be charged on that amount and added to the balance.
The most common example of a revolving account is a credit card.