利息是指借款人在欠款期间向贷款人支付的额外费用，用于抵消借款人持有债权的成本。它通常是用每年百分之几的固定比例计算的，并在每期还款中收取。

利息一词起源于拉丁语，其原意是「喜悦」或「欢乐」。在金融领域，它被用来描述借款人在欠款期间向贷款人支付的额外费用，以抵消借款人持有债权的成本。

例句：

This loan has a low interest rate, which means you'll pay less in interest over the life of the loan.

这笔贷款的利率较低，这意味着在贷款整个期间你的利息支出将会更少。

The bank is offering a special promotion where you can earn interest on your savings account.

银行正在提供一项特殊促销，可让你在储蓄账户上赚取利息。

Make sure to read the fine print on your loan agreement so you understand how much interest you'll be charged.

一定要仔细阅读贷款协议的细则，这样你才能了解你将被收取多少利息。