v. t. 1. To start (the engine of a motor vehicle) using a temporary connection to supply electrical power from another vehicle or another source of current; -- an emergency procedure used when a vehicle's own battery has insufficient power to start the vehicle normally. Cables used to transmit electrical current from one vehicle to another for the purpose of jump-starting are called jumper cables. [ PJC ]

2. To provide a speedy start to (an activity) using the assistance of some external impetus; to re-energize (an activity proceeding sluggishly); -- accomplished by application of a stimulus not normally used in the activity. [ Figurative ] [ PJC ]