\ ˈjak How to pronounce jack (audio) \
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

Keep scrolling for more

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

Visit the Thesaurus for More 

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

Against four spades, West led the jack and a second club. Frank Stewart, The Mercury News, "Bridge: June 10, 2019," 10 June 2019 Volunteer co-captains lead the group in a warm up of jumping jacks, squats and stretches. Jen Murphy, WSJ, "A Run to Get a Buddy Back on Track," 28 Apr. 2018 To say Selena Gomez is a jack-of-all-trades would be an understatement. Jennifer Lance, Glamour, "Selena Gomez Gave the Sweetest Toast at Her Bodyguard's Wedding," 5 May 2019 Apple is no longer selling the iPhone X or the iPhone SE and 6s, which means iPhones with headphone jacks are now extinct. Araceli Cruz, Teen Vogue, "iPhone X No Longer Available on Apple’s Website," 13 Sep. 2018 Even just doing some basic jumping jacks or doing some slow mountain climbers is better than nothing. SELF, "Full-Body Strength Push," 28 Apr. 2019 An oil pump jack pumps oil in a field near Calgary, Canada. Christopher Alessi, WSJ, "Oil Jumps Amid Volatile Market Activity," 28 Dec. 2018 The mic jack is a nod to musicians and likely YouTubers who prefer very high-end microphones. Gordon Mah Ung, PCWorld, "Exclusive first look: Creative Labs' high-end Sound BlasterX AE-9 breaks cover," 8 Dec. 2018 Like it or not, Apple is removing the headphone jack from the new 11-inch and 12.9-inch iPad Pros. Stefan Etienne, The Verge, "The new iPad Pro doesn’t have a headphone jack," 30 Oct. 2018

Recent Examples on the Web: Verb

Tariffs create uncertainty in the building industry Just the threat of more tariffs has created a new level of uncertainty and concern that builders will be forced to jack up prices even higher. Randy Tucker, Cincinnati.com, "Trump tariffs hit local homebuilders and buyers hard," 9 June 2019 Yet the PERS Board could just as easily go in the opposite direction, jacking up its assumed earnings rate and giving employers and lawmakers further budget relief. oregonlive.com, "Will PERS Board follow lawmakers’ lead on pension reform, or buck them?," 5 June 2019 Should Fekir have a strong tournament, more clubs could come in for the man set to replace Philippe Coutinho, and Lyon could easily jack up his price tag. SI.com, "Liverpool Desperate to Tie Down Wantaway Midfielder Nabil Fekir Before the World Cup Starts," 29 May 2018 Both are in total beast mode, jacked up and hulked out, ready to pop off at a moment’s notice. Katie Walsh, Detroit Free Press, "Review: Details bog down ‘Den of Thieves’," 18 Jan. 2018 Find your jacking point (usually just behind the front wheel opening at the front, and just ahead of the rear wheel opening at the rear) and jack the car up. Ezra Dyer, Popular Mechanics, "How to Rotate Your Tires," 13 Dec. 2018 In this case that meant the likes of feather-light cakes of local Jonah crabmeat, bound with artichoke, and jacked up with tangy celeriac slaw. Alexandra Hall, BostonGlobe.com, "At the heart of Woodfords Corner’s revival is this: ‘You don’t get very many opportunities in life to do what you really believe in’," 26 June 2018 But when a character put the headset on and entered another character’s consciousness, the aspect ratio widen to 70mm and the frame rate would jack up to 60: Everything would seem bigger, crisper, hyperreal. Eleanor Hildebrandt, Popular Mechanics, "The True Story of the Lost Sci-Fi Movie "Brainstorm," Natalie Wood’s Last Film," 21 Dec. 2018 Taxi drivers won’t rip you off, and no one will jack up the price at a restaurant or shop. Sarah Souli, Condé Nast Traveler, "Kosovo Is an All-Night Party—And Shows No Signs of Slowing Down," 26 Oct. 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.

See More

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

Keep scrolling for more

Learn More about jack

Statistics for jack

Last Updated

15 Jun 2019

Look-up Popularity

Time Traveler for jack

The first known use of jack was in 1548

See more words from the same year

Keep scrolling for more

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 How to pronounce jack (audio) \

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.

Keep scrolling for more

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).


showing courage and determination

Get Word of the Day daily email!

Test Your Vocabulary

Words for Summer: A Quiz

  • a closeup of a sunflower
  • Which of the following words means “of or relating to summer”?
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!