any of various portable devices for raising or lifting heavy objects short heights, using various mechanical, pneumatic, or hydraulic methods.

Also called knave. Cards . a playing card bearing the picture of a soldier or servant.

Electricity . a connecting device in an electrical circuit designed for the insertion of a plug.

( initial capital letter ) Informal . fellow; buddy; man (usually used in addressing a stranger)

Hey, Jack, which way to Jersey?

Also called jackstone. Games .

one of a set of small metal objects having six prongs, used in the game of jacks.

one of any other set of objects, as pebbles, stones, etc., used in the game of jacks.

jacks, ( used with a singular verb ) a children's game in which small metal objects, stones, pebbles, or the like, are tossed, caught, and moved on the ground in a number of prescribed ways, usually while bouncing a rubber ball.

any of several carangid fishes, esp. of the genus Caranx, as C. hippos (crevalle jack or jack crevalle), of the western Atlantic Ocean.

Slang . money

He won a lot of jack at the races.

Slang

Vulgar. jack shit.

Nautical .

a small flag flown at the jack staff of a ship, bearing a distinctive design usually symbolizing the nationality of the vessel.

Also called jack crosstree. either of a pair of crosstrees at the head of a topgallant mast, used to hold royal shrouds away from the mast.

( initial capital letter ) a sailor.

a lumberjack.

applejack.

jack rabbit.

a jackass.

jacklight.

a device for turning a spit.

a small wooden rod in the mechanism of a harpsichord, spinet, or virginal that rises when the key is depressed and causes the attached plectrum to strike the string.

Lawn Bowling . a small, usually white bowl or ball used as a mark for the bowlers to aim at.

Also called clock jack. Horology . a mechanical figure that strikes a clock bell.

a premigratory young male salmon.

Theater . brace jack.

Falconry . the male of a kestrel, hobby, or esp. of a merlin.

to lift or move (something) with or as if with a jack (usually fol. by up )

to jack a car up to change a flat tire.

Informal . to increase, raise, or accelerate (prices, wages, speed, etc.) (usually fol. by up ).

Informal . to boost the morale of; encourage (usually fol. by up ).

to jacklight.

to jacklight.

Carpentry . having a height or length less than that of most of the others in a structure; cripple

jack rafter; jack truss.

jack off, Slang

Vulgar to masturbate.

every man jack

everyone without exception

They presented a formidable opposition, every man jack of them.

noun

jack-tar , mariner , navigator , sea dog , seafarer , seaman , banderole , banner , banneret , color , ensign , oriflamme , pennant , pennon , standard , streamer , cash , currency , lucre

verb

boost , hike , jump , up