1. An industrial agreement made between an employer and local labor union officials containing terms beneficial to the employer without the knowledge of the employees, typically in exchange for money to the union or its leaders. It was later discovered that the union leader had made a sweetheart agreement with the company that eliminated employees' right to strike in exchange for a hefty yearly bonus for himself. The automotive manufacturer decided to move its factories to a different country, where it established a sweetheart agreement with the local labor union to pay workers substantially less than those previously enjoyed by American employees.

2. Any kind of agreement or contract that is mutually beneficial two the two parties directly involved, typically at the expense of a third party that is not privy to the agreement. It turns out the athletic director had in place a sweetheart agreement with the national athletics association, essentially receiving kickbacks every time one of his athletes performed well. The charity has come under fire for what some are calling a sweetheart agreement with a for-profit events organizer that receives nearly 40% of the annual donations the charity receives.