Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “jack”

See all translations

jack

noun [C] uk   /dʒæk/ us  

jack noun [C] (EQUIPMENT)

a piece of equipment that can be opened slowly under a heavy object such as a car in order to raise it off the ground: You need a car jack in order to change a tyre.

jack noun [C] (CARD)

( also knave) a playing card with a picture of a man on it. It has a lower value than the cards showing a king or queen: the jack of clubs

jack noun [C] (BALL)

a small ball towards which other balls are rolled or thrown in the games of bowls or boules

jack noun [C] (ELECTRICAL)

a connection between two pieces of electrical equipment
(Definition of jack from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of jack?
Add Cambridge dictionaries to your browser to your website

Definitions of “jack” in other dictionaries

Word of the Day

be as cold as ice

to be extremely cold

Word of the Day

Let’s celebrate! (words and phrases for parties)

by Kate Woodford,
December 17, 2014
​​​ With Christmas and New Year almost upon us, we thought it a good time to look at the language of parties and celebrations. First, let’s start with the word ‘party’ itself. To have or throw a party or, less commonly, to give a party is to arrange a party: We’re having a

Read More 

cinderella surgery noun

December 15, 2014
cosmetic surgery to the feet We have all heard of people having nose jobs, boob jobs and liposuction – but now a new trend growing in popularity in America: Cinderella surgery.

Read More