Payback is revenge or retaliation, the act of doing something harmful to someone because they hurt you first. When a student embarrasses their friend in front of the class, that friend might plot payback by telling an embarrassing story about them later. In movies, the hero often seeks payback against the villain who wronged them.

The word carries a sense of getting even, of balancing the scales. If someone plays a prank on you and you play one back on them, that's payback. The phrase payback time means the moment has arrived to settle a score.

Payback can also mean repaying money you borrowed. When you get payback on a loan, you're receiving the money back that you lent to someone. A company might calculate the payback period on an investment, meaning how long it takes to earn back the money they spent.

Notice the difference: revenge payback can make situations worse, creating cycles where people keep hurting each other back and forth. Financial payback, though, simply means getting back what you're owed.