Meaning of JACK in English

JACK

I

Any of more than 150 species of fishes (family Carangidae, order Perciformes) found in temperate and tropical portions of the Atlantic, Pacific, and Indian oceans and occasionally in fresh or brackish water.

Though body size and shape vary greatly, many species have small scales that create a smooth appearance, a laterally compressed body, rows of large spiky scales along the side near the tail fin, and a deeply forked tail. Many have a bluish green, silvery, or yellowish sheen. Jacks are important commercially and are favoured sport fishes. See also amberjack .

II

In practical mechanics , portable hand-operated device for raising heavy weights through short distances, exerting great pressures, or holding assembled work firmly in position.

The ratio of the load to the amount of force applied to the handle can be made quite high by using a gear or screw to regulate the upward extension. A ratchet allows a heavy weight to be raised in short successive stages. Though limited by the requirements of portability and ease of manual operation, jacks may lift, or exert a force of, several tons. A familiar example is the automobile jack, used to raise one end of a car to change a tire.

III

[c mediumvioletred] (as used in expressions)

Dempsey Jack

Gibson Eleanor Jack

Eleanor Jack

Jack the Ripper

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Johnson Jack

Kemp Jack French

Kerouac Jack

Kevorkian Jack

Kilby Jack St. Clair

Kramer Jack

Lemmon Jack

London Jack

Miner Jack

Nicholson Jack

Nicklaus Jack William

Paar Jack

Jack Roosevelt Robinson

Teagarden Jack

Britannica English dictionary.      Английский словарь Британика.