What does JACK stand for?

What does JACK mean?

JACK	Jack Audio Connection Kit Academic & Science » Electronics
JACK	Jack Audio Connection Kit Computing » Hardware
JACK	Just Another Concurrency Kit Computing » General
JACK	Computer generated icons Governmental » Military
JACK	Just Arts Club For Kids Community
JACK	Golden Bear Golf, Inc. ( Jack Nicklaus) Business » NASDAQ Symbols
JACK	Just Another Contract Killer Miscellaneous » Names and Nicknames
JACK	Jack In The Box Business » NYSE Symbols
Jack	Jaques Community
Jack	John Community
Jack	Jackson Community

jack(n.): any of various portable devices for raising or lifting heavy objects short heights, using various mechanical, pneumatic, or hydraulic methods: