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  1. any of various portable devices for raising or lifting heavy objects short heights, using various mechanical, pneumatic, or hydraulic methods.
  2. Also called knave. Cards. a playing card bearing the picture of a soldier or servant.
  3. Electricity. a connecting device in an electrical circuit designed for the insertion of a plug.
  4. (initial capital letter) Informal. fellow; buddy; man (usually used in addressing a stranger): Hey, Jack, which way to Jersey?
  5. Also called jackstone. Games.
    1. one of a set of small metal objects having six prongs, used in the game of jacks.
    2. one of any other set of objects, as pebbles, stones, etc., used in the game of jacks.
    3. jacks,(used with a singular verb)a children's game in which small metal objects, stones, pebbles, or the like, are tossed, caught, and moved on the ground in a number of prescribed ways, usually while bouncing a rubber ball.
  6. any of several carangid fishes, especially of the genus Caranx, as C. hippos (crevalle jack or jack crevalle), of the western Atlantic Ocean.
  7. Slang. money: He won a lot of jack at the races.
  8. Slang: Vulgar. jack shit.
  9. Nautical.
    1. a small flag flown at the jack staff of a ship, bearing a distinctive design usually symbolizing the nationality of the vessel.
    2. Also called jack crosstree.either of a pair of crosstrees at the head of a topgallant mast, used to hold royal shrouds away from the mast.
  10. (initial capital letter) a sailor.
  11. a lumberjack.
  12. applejack.
  13. jack rabbit.
  14. a jackass.
  15. jacklight.
  16. a device for turning a spit.
  17. a small wooden rod in the mechanism of a harpsichord, spinet, or virginal that rises when the key is depressed and causes the attached plectrum to strike the string.
  18. Lawn Bowling. a small, usually white bowl or ball used as a mark for the bowlers to aim at.
  19. Also called clock jack. Horology. a mechanical figure that strikes a clock bell.
  20. a premigratory young male salmon.
  21. Theater. brace jack.
  22. Falconry. the male of a kestrel, hobby, or especially of a merlin.
verb (used with object)
  1. to lift or move (something) with or as if with a jack (usually followed by up): to jack a car up to change a flat tire.
  2. Informal. to increase, raise, or accelerate (prices, wages, speed, etc.) (usually followed by up).
  3. Informal. to boost the morale of; encourage (usually followed by up).
  4. Slang. to mess up, ruin, or injure (usually followed by up): The paint job was all jacked up.I jacked my shoulder when I fell.
  5. to jacklight.
verb (used without object)
  1. to jacklight.
  1. Carpentry. having a height or length less than that of most of the others in a structure; cripple: jack rafter; jack truss.
Verb Phrases
  1. jack off, Slang: Vulgar. to masturbate.
  1. every man jack, everyone without exception: They presented a formidable opposition, every man jack of them.

Origin of jack1

1350–1400; Middle English jakke, Jakke used in addressing any male, especially a social inferior, variant of Jakken, variant of Jankin, equivalent to Jan John + -kin -kin; extended in sense to anything male, and as a designation for a variety of inanimate objects


verb (used with object) Slang.
  1. to steal: Some neighborhood kids jacked her car and took it for a joyride.Hackers jacked my email account in a phishing scam.
  2. to rob: He got jacked on his way home from the club.

Origin of jack2

First recorded in 1930–35; shortening of hijack


  1. jackfruit.

Origin of jack3

1605–15; < Portuguese jaca < Malayalam cakka


  1. a defensive coat, usually of leather, worn in medieval times by foot soldiers and others.
  2. a container for liquor, originally of waxed leather coated with tar.

Origin of jack4

1325–75; Middle English jakke < Middle French jaque(s), jacket, short, plain upper garment, probably after jacques peasant (see Jacquerie)


  1. a male given name, form of Jacob or John.


  1. JohnJack, 1917–1999, Irish political leader: prime minister 1966–73, 1977–79.


  1. Ber·na·dotte Ev·er·ly [bur-nuh-dot ev-er-lee] /ˈbɜr nəˌdɒt ˈɛv ər li/, 1886–1969, U.S. historian.
  2. Harrison (Ha·gan) [hey-guh n] /ˈheɪ gən/, Jack, born 1935, U.S. astronaut, geologist, and politician: U.S. senator 1977–83.


  1. Wel·don John [wel-dn] /ˈwɛl dn/, Jack, 1905–64, U.S. jazz trombonist and singer.


[brab-uh m]
  1. Sir John ArthurJack, 1926–2014, Australian racing-car driver and designer.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for jack

Contemporary Examples

Historical Examples

  • I—I am rather apologetic, Jack, because I didn't explain to you sooner.


    Mary Roberts Rinehart

  • Jack Bates looked up from emptying the third spoon of sugar into his coffee.

  • "Yes, that was another of Jack's fool schemes," put in Slim.

  • "I don't think you'll go alone," asserted Jack Bates, grabbing his hat.

  • "But Papa Jack would die befo' he'd take help from you," she wailed.

    The Little Colonel

    Annie Fellows Johnston

British Dictionary definitions for jack


  1. a man or fellow
  2. a sailor
  3. the male of certain animals, esp of the ass or donkey
  4. a mechanical or hydraulic device for exerting a large force, esp to raise a heavy weight such as a motor vehicle
  5. any of several mechanical devices that replace manpower, such as a contrivance for rotating meat on a spit
  6. one of four playing cards in a pack, one for each suit, bearing the picture of a young prince; knave
  7. bowls a small usually white bowl at which the players aim with their own bowls
  8. electrical engineering a female socket with two or more terminals designed to receive a male plug (jack plug) that either makes or breaks the circuit or circuits
  9. a flag, esp a small flag flown at the bow of a ship indicating the ship's nationalityCompare Union Jack
  10. nautical either of a pair of crosstrees at the head of a topgallant mast used as standoffs for the royal shrouds
  11. a part of the action of a harpsichord, consisting of a fork-shaped device on the end of a pivoted lever on which a plectrum is mounted
  12. any of various tropical and subtropical carangid fishes, esp those of the genus Caranx, such as C. hippos (crevalle jack)
  13. Also called: jackstone one of the pieces used in the game of jacks
  14. short for applejack, bootjack, jackass, jackfish, jack rabbit, lumberjack
  15. US a slang word for money
  16. every man jack everyone without exception
  17. the jack Australian slang venereal disease
  1. jack of Australian slang tired or fed up with (something)
verb (tr)
  1. to lift or push (an object) with a jack
  2. electrical engineering to connect (an electronic device) with another by means of a jack and a jack plug
  3. Also: jacklight US and Canadian to hunt (fish or game) by seeking them out or dazzling them with a flashlight
See also jack in, jacks, jack up

Word Origin

C16 jakke, variant of Jankin, diminutive of John



  1. short for jackfruit

Word Origin

C17: from Portuguese jaca; see jackfruit


  1. a short sleeveless coat of armour of the Middle Ages, consisting usually of a canvas base with metal plates
  2. archaic a drinking vessel, often of leather

Word Origin

C14: from Old French jaque, of uncertain origin


  1. I'm all right, Jack British informal
    1. a remark indicating smug and complacent selfishness
    2. (as modifier)an ``I'm all right, Jack'' attitude


  1. Sir John Arthur, known as Jack . born 1926, Australian motor-racing driver: Formula One world champion 1959, 1960, and 1966


  1. (tr) (of a mob) to punish (a person) for some supposed offence by hanging without a trial
Derived Formslyncher, nounlynching, noun

Word Origin

probably after Charles Lynch (1736–96), Virginia justice of the peace, who presided over extralegal trials of Tories during the American War of Independence


  1. David. born 1946, US film director; his work includes the films Eraserhead (1977), Blue Velvet (1986), Wild at Heart (1990), Mulholland Drive (2001), and Inland Empire (2006), and the television series Twin Peaks (1990)
  2. John, known as Jack Lynch. 1917–99, Irish statesman; prime minister of the Republic of Ireland (1966–73; 1977–79)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for jack


masc. proper name, 1218, probably an anglicization of Old French Jacques (which was a diminutive of Latin Jacobus; see Jacob), but in English the name always has been associated with Johan, Jan "John," and some have argued that it is a native formation.

Alliterative coupling of Jack and Jill is from 15c. (Ienken and Iulyan). In England, applied familiarly or contemptuously to anybody (especially one of the lower classes) from late 14c. Later used especially of sailors (1650s; Jack-tar is from 1781). In U.S., as a generic name addressed to an unknown stranger, attested from 1889.


late 14c., jakke "a mechanical device," from the masc. name Jack. The proper name was used in Middle English for "any common fellow" (mid-14c.), and thereafter extended to various appliances replacing servants (1570s). Used generically of men (jack-of-all-trades, 1610s), male animals (1620s, see jackass, jackdaw, etc.), and male personifications (1520s, e.g. Jack Frost, 1826).

As the name of a device for pulling off boots, from 1670s. The jack in a pack of playing cards (1670s) is in German Bauer "peasant." Jack shit "nothing at all" is attested by 1968, U.S. slang. The plant jack-in-the-pulpit is attested by 1837. Jack the Ripper was active in London 1888. The jack of Union Jack is a nautical term for "small flag at the bow of a ship" (1630s).


1860, jack up "hoist, raise," American English, from the noun (see jack (n.)). Figurative sense "increase (prices, etc.)" is 1904, American English. Related: Jacked; jacking. Jack off (v.) "to masturbate" is attested from 1916, probably from jack (n.) in the sense of "penis."



1835, from earlier Lynch law (1811), likely named after William Lynch (1742-1820) of Pittsylvania, Virginia, who c.1780 led a vigilance committee to keep order there during the Revolution. Other sources trace the name to Charles Lynch (1736-1796) a Virginia magistrate who fined and imprisoned Tories in his district c.1782, but the connection to him is less likely. Originally any sort of summary justice, especially by flogging; narrowing of focus to "extralegal execution by hanging" is 20c. Lynch mob is attested from 1838. The surname is perhaps from Irish Loingseach "sailor." Cf. earlier Lydford law, from a place in Dartmoor, England, "where was held a Stannaries Court of summary jurisdiction" [Weekley], hence:

Lydford law: is to hang men first, and indite them afterwards. [Thomas Blount, "Glossographia," 1656]

Related: Lynched; lynching.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with jack


In addition to the idioms beginning with jack

also see:

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.