首先，可以通过对关键词rollover + loan进行搜索的方式查找其英文释义。搜索结果如下：

Generally, renewing or rolling over a payday loan means you pay a fee to delay paying back the loan. This fee does not reduce the amount you owe. You will still owe the principal and fees for the rollover.

Loan rollover means extending your current loan into a new term, while adding more fees and interest. It’s a common practice for payday lenders and can lead borrowers into a cycle of debt that’s difficult to escape. 

A rollover is the renewal of a loan. Instead of liquidating a loan on maturity, you can roll it over into a new loan.

A rollover loan is a type of loan which is automatically renewed when it is not repaid in full within a predefined loan term.

由上可知，roll over基本等同于renew a loan，指的是通过支付一定的费用，推迟贷款还款日期。因而“roll over”可以理解为贷款的“展期”。

但“展期”这一理解并不适用于所有情况，比如，在维基百科对于revolving loan的定义中，此处的“rollover loan”则并不适合被译为“展期”：

A revolving loan made to refinance another revolving loan which matures on the same date as the drawing of the second revolving loan is known as a "rollover loan", if made in the same currency and drawn by the same borrower as the first revolving loan.

这句话大概的意思是若出于就某一到期的循环贷款还款之目的而于同一日提取第二笔循环贷款的，则第二笔贷款被称为“rollover loan”。在此情况下，将rollover译为展期显然是不合适的，因而在这里，很明显roll over相当于是借新还旧。因而，将其译为“滚转”更为合适。

知识拓展

循环信贷Revolving Credit

循环信贷又称周转信贷、周转信贷协议。循环贷款协定是银行具有法律义务地承诺提供不超过某一最高限额的贷款协定。在此限额内，客户可循环使用贷款资金。