A deferment delays something until a future time. If you want to wait a few years before paying off a loan, you need to ask for a deferment.
Deferment is an official word for "I'll do that later!" College students who owe a lot of money can apply for deferments that give them more time to pay back their loans. Students accepted to colleges can sometimes get a deferment that allows them to do something else first (like serve in the military), and then attend the college later. This is usually used in formal contexts — good luck getting a deferment for your chores.