prepay

动词 prepay:

1. pay for something before receiving it

1. I use a prepaid envelope.
   我用了一个邮资已付的信封。
2. The telegram was sent reply prepaid.
   电报已发出并已预付复电费用。

pre.pay

v.tr.（及物动词）
pre.paid,pre.pay.ing,pre.pays
To pay or pay for beforehand.
预付：预先付或为…付

【引伸】
prepay.ment
n.（名词）