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. (Zoöl.) (a) A young pike; a pickerel. (b) The jurel. (c) A large, California rock fish (Sebastodes
paucispinus); — called also boccaccio, and mérou. (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.
11. The knave of a suit of playing cards.
Jack is used adjectively in various senses. It sometimes designates something cut short or diminished
in size; as, a jack timber; a jack rafter; a jack arch, etc.
Jack arch, an arch of the thickness of one brick. — Jack back (Brewing & Malt Vinegar Manuf.),
a cistern which receives the wort. See under 1st Back. — Jack block (Naut.), a block fixed in the
topgallant or royal rigging, used for raising and lowering light masts and spars. — Jack boots, boots
reaching above the knee; — worn in the 17 century by soldiers; afterwards by fishermen, etc. — Jack
crosstree. (Naut.) See 10, b, above. — Jack curlew (Zoöl.), the whimbrel. — Jack frame. (Cotton
Spinning) See 4 (g), above. — Jack Frost, frost personified as a mischievous person. — Jack
hare, a male hare. Cowper. — Jack lamp, a lamp for still hunting and camp use. See def. 4 (n.),
above. — Jack plane, a joiner's plane used for coarse work. — Jack post, one of the posts which
support the crank shaft of a deep-well-boring apparatus. — Jack pot (Poker Playing), the name given
to the stakes, contributions to which are made by each player successively, till such a hand is turned
as shall take the "pot," which is the sum total of all the bets. — Jack rabbit (Zoöl.), any one of several
species of large American hares, having very large ears and long legs. The California species and that
of Texas and New Mexico (L. callotis), have the tail black above, and the ears black at the tip. They do
not become white in winter. The more northern prairie hare (L. campestris) has the upper side of the
tail white, and in winter its fur becomes nearly white. — Jack rafter (Arch.), in England, one of the
shorter rafters used in constructing a hip or valley roof; in the United States, any secondary roof timber,
as the common rafters resting on purlins in a trussed roof; also, one of the pieces simulating extended
rafters, used under the eaves in some styles of building. — Jack salmon (Zoöl.), the wall-eyed pike,
or glasseye. — Jack sauce, an impudent fellow. [Colloq. & Obs.] — Jack shaft (Mach.), the first
intermediate shaft, in a factory or mill, which receives power, through belts or gearing, from a prime
mover, and transmits it, by the same means, to other intermediate shafts or to a line shaft. — Jack
sinker (Knitting Mach.), a thin iron plate operated by the jack to depress the loop of thread between
two needles. — Jack snipe. (Zoöl.) See in the Vocabulary. — Jack staff (Naut.), a staff fixed on
the bowsprit cap, upon which the jack is hoisted. — Jack timber (Arch.), any timber, as a rafter, rib,
