/ dʒæk; NAmE / noun , verb , adjective
■ noun
1.
[ C ] a device for raising heavy objects off the ground, especially vehicles so that a wheel can be changed
2.
[ C ] an electronic connection between two pieces of electrical equipment
3.
[ C ] ( in a pack / deck of cards ) a card with a picture of a young man on it, worth more than a ten and less than a queen :
the jack of clubs
4.
[ C ] ( in the game of bowls ) a small white ball towards which players roll larger balls
5.
jacks [ pl. ] a children's game in which players bounce a small ball and pick up small metal objects, also called jacks , before catching the ball
6.
(also jack ˈshit , taboo ) [ U ] ( NAmE , slang ) (usually used in negative sentences) anything or nothing at all :
You don't know jack.
—see also blackjack , flapjack , Union Jack
•
IDIOMS
- a jack of all trades
—more at all right adjective , work noun
■ verb
•
PHRASAL VERBS
- jack sb around
- jack in / into sth
- jack sth in
- jack off
- jack up
- jack sth up
■ adjective
[ not before noun ] jack of sb/sth ( AustralE ) tired of or bored with sb/sth
••
WORD ORIGIN
late Middle English : from Jack , pet form of the given name John . The term was used originally to denote an ordinary man , also a youth (mid 16th cent.), hence the knave in cards and male animal . The word also denoted various devices saving human labour, as though one had a helper (sense 1, and in compounds such as jackhammer and jackknife ); the general sense labourer arose in the early 18th cent. and survives in lumberjack , steeplejack , etc. Since the mid 16th cent. a notion of smallness has arisen, hence senses 4 and 5.