a payment in addition to what is usual, necessary or expected, e.g. and extra payment to workers

unexpected extra

something given, offered or promised in order to influence or persuade a person (often to do something wrong)

payoff to influence illegal or wrong activity

a gift (of money in addition to pay or a pension) to a retiring employee for her or his activity

gift, tip

(of a person) to become (more) lively and active

benefit

advantages, such as a car, money in the form of paid expenses etc, given in addition to salary

benefit

(something given) in return for work or services, the returning of lost or stolen property, the capture of a criminal etc

payment, prize