Mechanical Engineering any of various portable devices for raising or lifting heavy objects a short distance off the ground:[countable]an automobile jack.
Games Also called knave. a playing card with the picture of a soldier or servant:[countable]a pair of jacks.
Electricity a connecting device in an electrical circuit designed so that a plug can be attached to it:[countable]a telephone jack.
Games
[countable] one of a set of small, six-pointed metal objects or pebbles used in the game of jacks.
jacks, [uncountable* used with a singular verb] a children's game in which a player tosses and gathers these objects usually while bouncing a small rubber ball.
v.
to lift or move (something) with or as if with a jack: [~ + object]to jack the car on the soft grass.[~ + up + object]to jack up a car.[~ + object + up]to jack it up.
Informal Termsto increase, raise, or accelerate (prices, wages, speed, etc.): [~ + up + object]The landlord jacked up rent illegally.[~ + object + up]They jacked oil prices up.
Idioms
every man jack, everyone without exception:The killers managed to escape, every man jack.
any of various portable devices for raising or lifting heavy objects short heights, using various mechanical, pneumatic, or hydraulic methods.
GamesAlso called knave.[Cards.]a playing card bearing the picture of a soldier or servant.
Electricitya connecting device in an electrical circuit designed for the insertion of a plug.
Informal Terms(cap.) fellow; buddy; man (usually used in addressing a stranger):Hey, Jack, which way to Jersey?
GamesAlso called jackstone.
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 sing. v.) 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.
Fishany of several carangid fishes, esp. of the genus Caranx, as C. hippos (crevalle jack or jack crevalle,) of the western Atlantic Ocean.
Slang Termsmoney:He won a lot of jack at the races.
Nautical
Naval Termsa small flag flown at the jack staff of a ship, bearing a distinctive design usually symbolizing the nationality of the vessel.
Naval TermsAlso 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.
Naval Terms(cap.) a sailor.
a lumberjack.
Wineapplejack.
MammalsSee 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.
Sport[Lawn Bowling.]a small, usually white bowl or ball used as a mark for the bowlers to aim at.
TimeAlso called clock jack.[Horol.]a mechanical figure that strikes a clock bell.
Fisha premigratory young male salmon.
Show Business[Theat.]See brace jack.
Sport[Falconry.]the male of a kestrel, hobby, or esp. of a merlin.
Idiomsevery man jack, everyone without exception:They presented a formidable opposition, every man jack of them.
v.t.
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 Termsto increase, raise, or accelerate (prices, wages, speed, etc.) (usually fol. by up).
Informal Termsto boost the morale of; encourage (usually fol. by up).
to jacklight.
v.i.
to jacklight.
Slang Termsjack off, Slang (vulgar). to masturbate.
adj.
Building[Carpentry.]having a height or length less than that of most of the others in a structure; cripple:jack rafter; jack truss.
1350–1400; Middle English jakke, Jakke used in addressing any male, esp. a social inferior, variant of Jakken, variant of Jankin, equivalent. to JanJohn + -kin -kin; extended in sense to anything male, and as a designation for a variety of inanimate objects
jack2( jak),USA pronunciationn.
Plant Biologyjackfruit.
Malayalam cakka
Portuguese jaca
1605–15
jack3( jak),USA pronunciationn.
a defensive coat, usually of leather, worn in medieval times by foot soldiers and others.
a container for liquor, originally of waxed leather coated with tar.
Middle French jaque(s), jacket, short, plain upper garment, probably after jacques peasant (see Jacquerie)