A merger, a sale or an agreement in which one party in the deal presents the other party with very attractive terms and conditions. The terms of a sweetheart deal are usually so lucrative that it is difficult to justify turning the offer down.

This term can be used to describe a variety of deals, but in general, a sweetheart deal is a transaction that simply can't be passed up. For example, a merger may be a sweetheart deal for the top executives of the target firm because they get very healthy buyout packages. This kind of sweetheart deal is usually considered unethical, however, because it may not be in the best interests of shareholders.