Jack

1. a device for lifting heavy objects, especially one for raising the axle of a motor vehicle off the ground so that a wheel can be changed or the underside inspected.
2. a playing card bearing a representation of a soldier, page, or knave, normally ranking next below a queen.
3. a socket with two or more pairs of terminals designed to receive a jack plug.
4. a small white ball in bowls, at which the players aim.
5. a game played by tossing and catching small round pebbles or star-shaped pieces of metal or plastic.
6. used to typify an ordinary man.

   he had that world-weary look of the working Jack who'd seen everything

7. a small version of a national flag flown at the bow of a vessel in harbour to indicate its nationality.
8. money.
9. a device for turning a spit.
10. a part of the mechanism in a spinet or harpsichord that connects a key to its corresponding string and causes the string to be plucked when the key is pressed down.
11. a marine fish that is typically laterally compressed with a row of large spiky scales along each side, important in many places as food or game fish.
12. the male of various animals, especially a merlin.
13. used in names of animals that are smaller than similar kinds, e.g. jack snipe.
14. short for jack shit.

late Middle English: from Jack, pet form of the given name John . The term was used originally to denote an ordinary man (jack¹ (sense 6)), also a youth (mid 16th century), hence the ‘knave’ in cards and ‘male animal’. The word also denoted various devices saving human labour, as though one had a helper (jack¹ (sense 1, sense 3, sense 9, sense 10), and in compounds such as jackhammer and jackknife); the general sense ‘labourer’ arose in the early 18th century and survives in cheapjack, lumberjack, steeplejack, etc. Since the mid 16th century a notion of ‘smallness’ has arisen, hence jack¹ (sense 4, sense 5, sense 7, sense 13).

1. another term for blackjack (sense 5).
2. a sleeveless padded tunic worn by foot soldiers.

1. take (something) illicitly; steal.

   what's wrong is to jack somebody's lyrics and not acknowledge the fact

1990s: from hijack.

1. tired of or bored with someone or something.

   people are getting jack of strikes

late 19th century: from jack up ‘give up’ (see jack up).