Пример употребления: A unilateral agreement is where one party makes a promise, declaration or offer. For example, a radio station DJ tells the audience that he will pay a listener $100 if he can answer a question. The radio station is the promisor and the listener is the promisee. The two sides of the agreement are not equal or mutual. The promisor offers money and the promisee must offer an answer.
(thelawdictionary.org).