You are John Rugby, and you are Jack Rugby. --Shak.
2. An impertinent or silly fellow; a simpleton; a boor; a
clown; also, a servant; a rustic. ``Jack fool.''
--Chaucer.
Since every Jack became a gentleman, There 's many a
gentle person made a Jack. --Shak.
3. A popular colloquial name for a sailor; -- called also
{Jack tar}, and {Jack afloat}.
4. 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; as:
(a) A device to pull off boots.
(b) A sawhorse or sawbuck.
(c) A machine or contrivance for turning a spit; a smoke
jack, or kitchen jack.
(b) (Mining) A wooden wedge for separating rocks rent by
blasting.
(e) (Knitting Machine) A lever for depressing the sinkers
which push the loops down on the needles.
(f) (Warping Machine) A grating to separate and guide the
threads; a heck box.
(g) (Spinning) A machine for twisting the sliver as it
leaves the carding machine.
(h) A compact, portable machine for planing metal.
(i) A machine for slicking or pebbling leather.
(k) A system of gearing driven by a horse power, for
multiplying speed.
(l) A hood or other device placed over a chimney or vent
pipe, to prevent a back draught.
(m) In the harpsichord, an intermediate piece
communicating the action of the key to the quill; --
called also {hopper}.
(n) In hunting, the pan or frame holding the fuel of the
torch used to attract game at night; also, the light
itself. --C. Hallock.
5. 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.
6. The small bowl used as a mark in the game of bowls.
--Shak.
Like an uninstructed bowler who thinks to attain the
jack by delivering his bowl straight forward upon
it. --Sir W.
Scott.
7. The male of certain animals, as of the ass.
8. (Zo["o]l.)
(a) A young pike; a pickerel.
(b) The jurel.
(c) A large, California rock fish ({Sebastodes
paucispinus}); -- called also {boccaccio}, and
{m['e]rou}.
(d) The wall-eyed pike.
9. A drinking measure holding half a pint; also, one holding
a quarter of a pint. [Prov. Eng.] --Halliwell.
10. (Naut.)
(a) 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.
(b) 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}. --R. H.
Dana, Jr.