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.

a playing card bearing a representation of a soldier, page, or knave, normally ranking next below a queen.

a socket designed to receive a jack plug.

a plug used in a jack socket, consisting of a shaft used to make a connection that transmits a signal, typically used in sound equipment.

in lawn bowling, the small ball at which the players aim.

a game played by tossing and catching small round pebbles or star-shaped pieces of metal or plastic.

a small version of a national flag flown at the bow of a vessel in harbor to indicate its nationality.

money.

a device for turning a spit.

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.

a marine fish that is typically laterally compressed with a row of large spiky scales along each side. Jacks are important in many places as food or game fish.

the male of some animals, especially a merlin or an ass.

used in names of animals that are smaller than similar kinds, e.g., jacksnipe.

short for jack shit.