Jack

From Middle English jakke ("any mechanical device"), from the name Jack, from Old French Jacques

Full definition of jack

(plural jacks)

A mechanical device used to raise and (temporarily) support a heavy object, eg. screw jack, scissor jack, hydraulic jack, ratchet jack, scaffold jack.She used a jack to lift her car and changed the tire.
A man or men in general.Every man jack.
A male animal.
(card games) The card ranking between the ten and queen of any suit, picturing a knave or prince on its face. In some card games has a value of eleven based on its rank, but in many card games has a value of ten like the ten, queen, and king cards. Also called a knave.
(archaic) A knave (a servant or later, a deceitful man).
(zoology) A male ass.
, related to the mango tree.
A surface-mounted connector for electrical, especially telecommunications, equipment.telephone jack
(sports) A target ball in bowls, etc; a jack-ball.

unknown date, Sir Walter Scottlike an uninstructed bowler who thinks to attain the jack by delivering his bowl straight forward upon it

(games) A small, six-pointed playing piece used in the game of jacks.
(colloquial) Nothing, jackshit.You haven't done jack. Get up and get this room cleaned up right now!
(nautical) A small flag at the bow of a ship.
(nautical) A naval ensign flag flown from the main mast, mizzen mast, or the aft-most major mast of (especially) British sailing warships; Union Jack.
(military) A coarse and cheap medieval coat of defense, especially one made of leather.

1786, Francis Grose, A Treatise on Ancient Armour and Weapons, The aketon, gambeson, vambasium, and jack were military vestments, calculated for the defence of the body, differing little from each other, except in their names, their materials and construction were nearly the same, the authorities quoted in the notes, shew they were all composed of many folds of linen, stuffed with cotton, wool or hair, quilted, and commonly covered with leather, made of buck or doe skin.

(two-up) A penny with a head on both sides, used for cheating. (Reference: Sidney J. Baker, The Australian Language, second edition, 1966, chapter XI section 3, page 243.)
(slang) Money.

1939, Raymond Chandler, The Big Sleep, Penguin 2011, p. 133:First off Regan carried fifteen grand, packed it in his clothes all the time. Real money, they tell me. Not just a top card and a bunch of hay. That's a lot of jack ....

(slang, Appalachians) A smooth often ovoid large gravel or small cobble in a natural water course.
A common name for the freshwater pike, green pike or pickerel.
A large California rockfish.
Any marine fish or the species of the Carangidae family.
(obsolete, nautical) A sailor; a "jack tar".
(obsolete) A pitcher or can of waxed leather, supposed to resemble a jackboot; a black-jack.
(UK, dialect, obsolete) A drinking measure holding half a pint or, sometimes, a quarter of a pint.
A mechanical contrivance, an auxiliary machine, or a subordinate part of a machine.

A device to pull off boots.
A sawhorse or sawbuck.
A machine for turning a spit; a smokejack.
(mining) A wooden wedge for separating rocks rent by blasting.
A lever for depressing the sinkers which push the loops down on the needles in a knitting machine.
A grating to separate and guide the threads in a warping machine; a heck box.
A machine for twisting the sliver as it leaves the carding machine.
A compact, portable machine for planing metal.
A machine for slicking or pebbling leather.
A system of gearing driven by a horse power, for multiplying speed.
A hood or other device placed over a chimney or vent pipe, to prevent a back draught.
In the harpsichord, an intermediate piece communicating the action of the key to the quill; also called hopper.
In hunting, the pan or frame holding the fuel of the torch used to attract game at night; also, the light itself.
(nautical) A bar of iron athwart ships at a topgallant masthead, to support a royal mast, and give spread to the royal shrouds; also called jack crosstree.

(transitive) To use a jack.He jacked the car up so that he could replace the brake pads.
(transitive) To raise or increase.If you want to jack your stats you just write off failures as invalid results.
(transitive, colloquial) To steal something, typically an automobile. Contraction of carjackingSomeone jacked my car last night!
(intransitive) To dance by moving the torso forward and backward in a rippling motion.

(transitive, slang, baseball) To hit (the ball) hard; especially, to hit (the ball) out of the field, producing a home run.

1986, in Arete: The Journal of Sport Literature, Volume 4, Sport Literature Association:An excellent piece of work, Wayne thought, so good in fact, he wasnâ€™t surprised when Bailey walked to the plate and on the first pitch jacked the ball far into the parking lot outside the left-field fence for a tournament winning homerun.
2004, Wayne Stewart, Hitting Secrets of the Pros: Big League Sluggers Reveal the Tricks of Their Trade, McGraw-Hill Professional, ISBN 9780071418249, page 90:Therefore, even though Vizquel is certainly not a power hitter, at times he will try to jack the ball, perhaps pulling it with just enough oomph to carry down the line for a homer.
a. 2009 Jim McManus, quoted in T.J. Lewis, A View from the Mound: My Fatherâ€™s Life in Baseball, Lulu.com (publisher, 2008), ISBN 9781435714861, page 107:Maybe he hung a curve ball to somebody and they jacked it out of the park on him and he wasnâ€™t upset about it.

French jaque, jacque, perhaps from the proper name Jacques. Compare jacquerie.

(plural jacks)

(plural jacks)