Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “jack”


noun [C]     /dʒæk/
EQUIPMENT a piece of equipment for lifting a heavy object such as a carMachinery and machinesHousehold equipment and domestic chores
PLAYING CARD a playing card that comes between a ten and a queen: the jack of diamondsPlaying cards
(Definition of jack noun from the Cambridge Learner's Dictionary © Cambridge University Press)

Definitions of “jack” in other dictionaries

Word of the Day


When a boat or a ship sails, it travels on the water.

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More