jack

1 of 2

noun

plural jacks
1
a
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
2
a
: 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
5
a
or less commonly Jack chiefly British : man
usually used as an intensive
every man jack in the team will want to impress their new manager.Malcolm Macdonald
Those two sessions were both open to the public, which meant that any man Jack from the street could have walked in to watch …Neil Ashton
b
or Jack : sailor
c(1)
(2)
6
: something that supports or holds in position: such as
a
: an iron bar at a topgallant masthead to support a royal (see royal entry 1 sense 4) mast and spread the royal shrouds (see shroud entry 1 sense 3a)
b
: a wooden brace fastened behind a scenic unit in a stage set to prop it up
7
a
: any of several fishes
especially : any of various carangids (such as a jack crevalle)
b
: a male donkey
d
: any of several birds (such as a jackdaw)
8
a
: a small usually white target ball used in lawn bowling or bocce
b
: a small national flag flown by a ship
9
slang : money
10
a
b
: brandy
11
12
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

jack

2 of 2

verb

jacked; jacking; jacks

transitive verb

1
: to move or lift (something) by or as if by a jack (see jack entry 1 sense 3a) : jack up
It meant that we had to jack the aircraft and check out the undercarriage system …John Revell
Over 500 tons of pressure was used to jack the legs of the [Gateway] Arch apart for the last four-foot piece to be inserted at the top.nps.gov
2
a
: to raise the level or amount of (something) : increase, jack up
The company jacked their rates.
b
: to increase in intensity, scope, etc. : jack up
In the same light, any student has heard of someone taking self-prescribed Adderall to jack their focus for the next big exam.Zeno Yeates
3
a
informal : steal
"She jacked my pencil" one boy screamed. "But only because he jacked my pen" the girl yelled back.Jason Kane
especially : to steal (a car)
A man is accused of stealing from a Bradenton hardware store and then jacking a nearby car … Giuseppe Sabella
b
informal : rob
jack a store
Droopy was always promising to rob old ladies, but so far had jacked only a pizza delivery man …Gini Sikes
4
informal : to cause great excitement, enthusiasm, or energy in : jack up
Even Phil Mickelson, the Masters champion of a year ago and a three-time winner in 2005, can't jack the audience like Woods.Gerry Dulac
5
: to hunt or fish for (an animal) at night with a jacklight or similar bright light
… if old-fashioned country stores were anything like ours is today, you could find just about any type of gossip you might want, from suspicions about who is jacking deer out of season to the darkest speculation about marital infidelities.Cook's Illustrated
6
informal : to copy or appropriate (something, such as an idea or style) : hijack sense 2a
Apparently I'd struck a nerve in that sensitive place called the male ego. In his mind I'd accused him of hip-hop's equivalent of treason—jacking someone's style.Dream Hampton
7
informal : to hit (a ball) forcefully
Five batters later Martinez jacked an upper-deck grand slam off Mark Langston …Tom Verducci
Big Mac turns it up another notch, jacking five homers in his last 11 at-bats to finish with an unreal 70.ESPN
… Mickelson took an aggressive line off the tee and jacked a lob wedge over the green.Alan Shipnuck
8
a
informal : to grab, shove, or handle (someone or something) forcefully : jack up
Behind the building he was greeted by several bruisers looking for blood. "One guy jacked my horn out of my arms and threw it down," he [Ornette Coleman] says.David Grogan
b
informal : to cause injury to (someone or something) : jack up
The next week, he jacked his knee in a practice incident …, and it set him back a bit.racerxonline.com
c
informal : to beat up or hurt (someone) : jack up
Cejudo dropped Cruz with that knee and was jacking him with punches with no real response from Cruz.Dan Bernstein
d
informal : to treat or confront (someone) in a harassing, rough, or overly aggressive and typically unwarranted manner : jack up
"I honestly think the only reason I get jacked by the police is because I'm tall and black," said Maurice [St. Cyere], who is 5'9".The Bay State Banner
9
vulgar : masturbate, jack off

intransitive verb

: to hunt or fish at night with a jacklight or similar bright light
"… jacking involves the use of a high-powered light and a firearm at night. … Whether you are successful in getting a deer or not, it is an illegal act."Blaine Henshaw
jacker noun

see also jacked, jack in, jack into

Examples of jack in a Sentence

Noun I'd buy that watch, but I don't have the jack right now. a Portuguese ship flying the national jack Verb jack up the car so we can change that tire local restaurants jacked up their prices for the summer tourist season
Recent Examples on the Web
These examples are automatically compiled from online sources to illustrate current usage. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Noun
On the front, the Mac mini has two USB-C 3.1 ports and a 3.5mm headphone jack. Brian Westover, PCMAG, 1 Nov. 2024 These ATMs deliver private spoken instructions in English or Spanish through a headset that plugs into an audio jack. Andreina Rodriguez, CNBC, 19 Oct. 2024
Verb
Gold prices slumped in April last year when the Fed started to jack up interest rates in its bid to tame runaway inflation. Nicole Goodkind, CNN, 12 Jan. 2023 So why not jack up 18 treys in the first half against Kennesaw State at Viejas Arena? Mark Zeigler, San Diego Union-Tribune, 12 Dec. 2022 See all Example Sentences for jack 

Word History

Etymology

Noun

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

First Known Use

Noun

1548, in the meaning defined at sense 5a

Verb

1833, in the meaning defined at intransitive sense 2

Time Traveler
The first known use of jack was in 1548

Dictionary Entries Near jack

Cite this Entry

“Jack.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/jack. Accessed 17 Nov. 2024.

Kids Definition

jack

1 of 2 noun
1
b
often capitalized : sailor
2
a
: a device for turning a spit (as in roasting meat)
b
: any of various portable devices for applying pressure or lifting a heavy body (as an automobile or a building) a short distance
3
: any of various animals: as
a
: a male donkey
4
a
: a small national flag flown by a ship
b
: a small six-pointed metal object used in a game
c
plural : a game played with jacks
5
: a playing card bearing the figure of a soldier or servant
6
slang : money sense 1a
7
: a socket used with a plug to connect one electric circuit with another

jack

2 of 2 verb
1
: to move or lift by or as if by a jack
2
: increase entry 1 sense 1, raise
jack up prices
jacker noun

More from Merriam-Webster on jack

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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