Other forms: prepaying; prepays
When you cover the cost of something before you actually have it, you prepay. You'll have to prepay now for that new refrigerator — even though they won't deliver it for two months!
You have to prepay for most things you purchase online or over the phone; your credit card is charged long before you can actually wear those new shoes or eat that takeout Thai food. Another way to prepay is to settle a bill early, before payment is due: "I'm going to prepay my rent through August." Pre- means "before," so whenever you pay beforehand, you prepay.