I. jack 1 /dʒæk/ BrE AmE noun [countable]
[ Date: 1300-1400 ; Origin: From the man's name Jack ]
1 . a piece of equipment used to lift a heavy weight off the ground, such as a car, and support it while it is in the air:
a hydraulic jack
2 . a card used in card games that has a man’s picture on it and is worth less than a queen and more than a ten
jack of hearts/clubs etc
a pair of jacks
3 . an electronic connection for a telephone or other electric machine:
a phone jack
a) jacks [plural] a children’s game in which the players try to pick up small objects called jacks while ↑ bouncing and catching a ball
b) a small metal or plastic object that has six points, used in this game
5 . a small white ball at which players aim larger balls in the game of ↑ bowl s
6 . jack (shit) American English spoken not polite a rude expression meaning anything at all:
He doesn’t know jack shit about cars.
⇨ ↑ jumping jack , ↑ Union Jack
II. jack 2 BrE AmE verb
jack somebody around phrasal verb
American English spoken to waste someone’s time by deliberately making things difficult for them:
Stop jacking me around and make up your mind!
jack something ↔ in phrasal verb
British English informal to stop doing something:
I’d love to jack in my job and go and live in the Bahamas.
jack off phrasal verb
American English informal not polite to ↑ masturbate
jack something ↔ up phrasal verb
1 . to lift something heavy off the ground using a jack:
Jack the car up higher – I can’t get the tire off.
2 . informal to increase prices, sales etc by a large amount:
They’re just interested in jacking up their profit margins.