jumper

1. Someone or something that jumps, e.g. a participant in a jumping event in track or skiing.
2. A person who attempts suicide by jumping from a great height.
3. A short length of electrical conductor, to make a temporary connection. · .
4. An electrical connection between the vehicles of a train, usually a passenger train; a jumper cable.
5. A removable connecting pin on an electronic circuit board.
6. A long drilling tool used by masons and quarry workers, consisting of an iron bar with a chisel-edged steel tip at one or both ends, operated by striking it against the rock, turning it slightly with each blow.
7. A crude kind of sleigh, usually a simple box on runners which are in one piece with the poles that form the thills. (US)
8. A jumping spider. (informal)

Plural jumpers