A mutual understanding between two or more legally competent individuals or entities about their rights and duties regarding their past or future performances and consideration. While an agreement usually leads to a 19 agreement contract, it could also be an executed sale, a gift or other transfer of property, or a promise without a legal obligation.  The understanding between two or more legally competent individuals or entities about the rights and duties regarding their past or future performances and consideration as manifested by their language (oral or written) or by implication from other circumstances such as the usage of trade and the course of performance. See also contract.