an advantage or profit that you get as a result of doing something:
With electric cars there is a big environmental payoff.
a payment that is made to someone, often illegally, in order to stop them from causing you trouble [↪ bribe]:
Union leaders allegedly received huge payoffs from the company's bosses.
a payment made to someone when they are forced to leave their job [↪ redundancy]:
The average payoff to staff was about £2000.