commercial frustration
n. an unforeseen uncontrollable event which occurs after a written or oral contract is entered into between parties, and makes it impossible for one of the parties to fulfill his/her duties under the contract. This circumstance allows the frustrated party to rescind the contract without penalty. Such frustration (called frustration of purpose) could include the destruction by fire of the goods to be purchased, the denial of a permit to construct a building by a potential buyer, or denial of an application for a zoning variance to allow expansion by a contractor.