General Definition: 1. The action of holding onto a bar or pole-like object, which is more or less horizontal, such as the arm of a water pump, and pushing it repeatedly up and down, or any action or any thing directly or indirectly related to this, especially a car jack. As a Noun: 1. A mechanical device that is used to lift a heavy object, especially a car, off the ground. English = jack. As a Verb or Adjective: 1. To lift a heavy object, especially a car, off the ground by using a special mechanical device. English = jack up.