"Jack" is a word in LAW AND LEGAL, ENGLISH

A kind of defensive coat-armor worn by horsemen in war; not made of solid iron, but of many plates fastened together. Some tenants were bound by their tenure to find lt upon Invasion. Cowell

The wall-eyed pike.

A sawhorse or sawbuck.

The jurel.

In hunting, the pan or frame holding the fuel of the torch
used to attract game at night; also, the light itself.

A young pike; a pickerel.

A machine or contrivance for turning a spit; a smoke jack, or
kitchen jack.

An impertinent or silly fellow; a simpleton; a boor; a clown;
also, a servant; a rustic.

In the harpsichord, an intermediate piece communicating the
action of the key to the quill; -- called also hopper.

The small bowl used as a mark in the game of bowls.

A familiar nickname of, or substitute for, John.

The male of certain animals, as of the ass.

A grating to separate and guide the threads; a heck box.

A popular colloquial name for a sailor; -- called also Jack
tar, and Jack afloat.

To move or lift, as a house, by means of a jack or jacks.
See 2d Jack, n., 5.

A pitcher or can of waxed leather; -- called also black jack.

A bar of iron athwart ships at a topgallant masthead, to
support a royal mast, and give spread to the royal shrouds; -- called
also jack crosstree.

A device to pull off boots.

A system of gearing driven by a horse power, for multiplying
speed.

A lever for depressing the sinkers which push the loops down
on the needles.

A large, California rock fish (Sebastodes paucispinus); --
called also boccaccio, and merou.

To hunt game at night by means of a jack. See 2d Jack, n.,
4, n.

A portable machine variously constructed, for exerting great
pressure, or lifting or moving a heavy body through a small distance.
It consists of a lever, screw, rack and pinion, hydraulic press, or any
simple combination of mechanical powers, working in a compact pedestal
or support and operated by a lever, crank, capstan bar, etc. The name
is often given to a jackscrew, which is a kind of jack.

A flag, containing only the union, without the fly, usually
hoisted on a jack staff at the bowsprit cap; -- called also union jack.
The American jack is a small blue flag, with a star for each State.

A machine for twisting the sliver as it leaves the carding
machine.

A drinking measure holding half a pint; also, one holding a
quarter of a pint.

A large tree, the Artocarpus integrifolia, common in the East
Indies, closely allied to the breadfruit, from which it differs in
having its leaves entire. The fruit is of great size, weighing from
thirty to forty pounds, and through its soft fibrous matter are
scattered the seeds, which are roasted and eaten. The wood is of a
yellow color, fine grain, and rather heavy, and is much used in
cabinetwork. It is also used for dyeing a brilliant yellow.

A machine for slicking or pebbling leather.

A coarse and cheap mediaeval coat of defense, esp. one made
of leather.

A hood or other device placed over a chimney or vent pipe, to
prevent a back draught.

A compact, portable machine for planing metal.

The knave of a suit of playing cards.

A wooden wedge for separating rocks rent by blasting.

A mechanical contrivance, an auxiliary machine, or a
subordinate part of a machine, rendering convenient service, and often
supplying the place of a boy or attendant who was commonly called Jack