As a Noun: 1. Two thick wires with clamps at each end that can be used when a car will not start because its battery does not have enough power. They are used to connect the battery to the battery of another car. English = jumper leads. 2. A device that produces electricity in a car. English = car battery. 3. As a Verb or Adjective: 1. To attach jumper leads to a car battery.