\ ˈjak \
plural jacks

Definition of jack

 (Entry 1 of 2)

1a jacks plural in form but singular in construction : a game played with a set of small objects that are tossed, caught, and moved in various figures
b : a small 6-pointed metal object used in the game of jacks
2a : a playing card carrying the figure of a soldier or servant and ranking usually below the queen
3 : any of various usually mechanical devices: such as
a : a usually portable mechanism or device for exerting pressure or lifting a heavy body a short distance
b : a device for turning a spit
4 : a female fitting in an electric circuit used with a plug to make a connection with another circuit
5a : man usually used as an intensive in such phrases as every man jack
b often capitalized : sailor
c(1) : servant, laborer
(2) : lumberjack
6 : something that supports or holds in position: such as
a : an iron bar at a topgallant masthead to support a royal mast and spread the royal shrouds
b : a wooden brace fastened behind a scenic unit in a stage set to prop it up
7a : any of several fishes especially : any of various carangids
b : a male donkey
d : any of several birds (such as a jackdaw)
8a : a small white target ball in lawn bowling
b : a small national flag flown by a ship
9 slang : money
10a : applejack
b : brandy
13 US slang : anything at all used in negative constructions In short, Dinger or Homer or whoever it was who wrote the Odyssey didn't know jack about travel.— Steve Rushin


jacked; jacking; jacks

Definition of jack (Entry 2 of 2)

transitive verb

1a : to move or lift by or as if by a jack
b : to raise the level of usually used with up jack up the price
c : to take to task
2 : to hunt or fish for at night with a jacklight

intransitive verb

: to hunt or fish at night with a jacklight

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Other Words from jack


jacker noun

Synonyms for jack

Synonyms: Noun

bread [slang], bucks, cabbage [slang], cash, change, chips, coin, currency, dough, gold, green, kale [slang], legal tender, lolly [British], long green [slang], loot, lucre, money, moola (or moolah) [slang], needful, pelf, scratch [slang], shekels (also sheqels), tender, wampum

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Examples of jack in a Sentence


I'd buy that watch, but I don't have the jack right now. a Portuguese ship flying the national jack

Recent Examples on the Web: Noun

The semi jack-knifed and hit the highway's cement median. Cliff Pinckard, cleveland.com, "Video shows fiery wrong-way crash on Texas highway," 23 Apr. 2018 Allen also noted that multiple 18-wheelers had jack-knifed on U.S. 59 at Hillcroft, prompting closures there. Meagan Flynn, Houston Chronicle, "Houston-area roads remain 'treacherous'," 17 Jan. 2018 Downtown bridges were closed at one point in Nashville and jack-knifed tractor-trailers dotted interstates throughout the city and surrounding area. Doug Stanglin, USA TODAY, "Shivering South braces for another wintry blast next week," 13 Jan. 2018 Sources: the company (photo); WSJ analysis of the laptop No computer is perfect for everyone, but in my testing the best overall option, the jack of all slate trades, is Microsoft’s new Surface Pro 6. David Pierce, WSJ, "Part Tablet, Part Laptop: Make Your Next Computer a Slate PC," 2 Dec. 2018 And add wireless charging, IP 68 water resistance, and possibly the removal of the headphone jack. Michael Simon, PCWorld, "Samsung Galaxy S10 rumors: It won't have a notch but it might have... a hole?," 13 Nov. 2018 The plyometric element of the squat jacks provides additional strength and cardio benefits. Jenny Mccoy, SELF, "Strengthen Your Legs and Butt With These 2 Bodyweight Exercises From Celebrity Trainer Jeanette Jenkins," 15 Aug. 2018 The vomiting pumpkin—in which green foam spews from a jack-o-lantern’s mouth—has become her signature effect. Don Steinberg, WSJ, "The Female Scientist Who Wants to Blow Up Your TV," 5 Dec. 2018 There are more than 40 varieties of caladiums, which are in the jack-in-the pulpit family. Bonnie Gross, Sun-Sentinel.com, "Local color: Lake Placid Caladium Festival," 3 July 2018

Recent Examples on the Web: Verb

Adding sweeteners, cream, and other mix-ins can quickly jack up the total. Caroline Picard, Good Housekeeping, "21 Surprising Coffee Facts That Will Perk Up Your Afternoon," 3 Dec. 2018 Shaft drive on some motorcycles can produce a clunky, jacking effect in the driveline, but the Ryker was easy. Ben Stewart, Popular Mechanics, "8 Cool Things About the Can-Am Ryker," 13 Nov. 2018 Does jacking up rents fit UCSC’s mission of keeping young companies in Philadelphia? Joseph N. Distefano, Philly.com, "Big rent hikes could force out labs and biotech start-ups at University City Science Center," 31 May 2018 Most of the time with these one-way sales, return flight prices are jacked way up, but departing and return flights from San Juan cost the same in Southwest's sale. Bridget Hallinan, Condé Nast Traveler, "Southwest Airlines Three Day Sale: One-Way Tickets from $49," 2 Oct. 2018 Think of it like jacking into the Matrix, but without all the metal bits inserted in your skull, maybe? Brad Chacos, PCWorld, "Witness the Acer Predator Thronos: A hulking triple-monitor simstation for PC gamers," 29 Aug. 2018 The trio often stepped out together post-workout, glowing, drenched in sweat; the pop star’s jacked forearms pictured in colorful tanks were enough to become tabloid talk all on their own. Liana Satenstein, Vogue, "At 60, Madonna Still Has the Best Arms in Hollywood," 16 Aug. 2018 Second, crypto-jacking is harder to detect and is more anonymous than other hacks. Robert Stevens, chicagotribune.com, "How your smart fridge and TV might be mining bitcoin for criminals," 4 July 2018 MFIs, for their part, found new clients among those their normal lending criteria excluded—without jacking up interest rates. The Economist, "Bucks after the bangHow microcredit can help poor countries after natural disasters," 25 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'jack.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of jack


1548, in the meaning defined at sense 5a


circa 1833, in the meaning defined at intransitive sense

History and Etymology for jack


Middle English Jacke, familiar term of address to a social inferior, nickname for Johan John

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Statistics for jack

Last Updated

12 Jan 2019

Look-up Popularity

Time Traveler for jack

The first known use of jack was in 1548

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More Definitions for jack



English Language Learners Definition of jack

: a device used for lifting something heavy (such as a car)

: a playing card that has a picture of a soldier or servant and that is worth more than a ten and less than a queen

: a small opening where something connects with a wire to something else


\ ˈjak \

Kids Definition of jack

 (Entry 1 of 2)

1 : a device for lifting something heavy a short distance
2 : a playing card with the picture of a young man
3 : a small six-pointed usually metal object used in a children's game ( jacks )
4 : a socket used with a plug to connect one electric circuit with another


jacked; jacking

Kids Definition of jack (Entry 2 of 2)

: to move or lift with a special device We need to jack up the car.

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More from Merriam-Webster on jack

Rhyming Dictionary: Words that rhyme with jack

Thesaurus: All synonyms and antonyms for jack

Spanish Central: Translation of jack

Nglish: Translation of jack for Spanish Speakers

Britannica English: Translation of jack for Arabic Speakers

Britannica.com: Encyclopedia article about jack

Comments on jack

What made you want to look up jack? Please tell us where you read or heard it (including the quote, if possible).


to settle judicially or to act as judge

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