› [U] LAW, FINANCE the right to pay a person or organization less money than you owe them because they also owe you money: What is the position regarding the offset of one debt against the other? › [C] ACCOUNTING a payment that is used to reduce the effect of another payment: The Australian government has announced changes to its tax offset rules for overseas production. › [C or U] ENVIRONMENT, SOCIAL RESPONSIBILITY a payment that is made or an action that is done in order to pay for or reduce the harmful effect that something has on the environment: carbon offset You have the opportunity to purchase an offset when you book your flights.