This word is frequently used in the formation of self- explaining
compounds; as, rock-bound, rock-built, rock-ribbed, rock-roofed, and
the like.
Rock alum. [Probably so called by confusion with F. roche a rock.] Same
as Roche alum. -- Rock barnacle (Zoöl.), a barnacle (Balanus
balanoides) very abundant on rocks washed by tides. -- Rock bass.
(Zoöl.) (a) The stripped bass. See under Bass. (b) The goggle-eye. (c)
The cabrilla. Other species are also locally called rock bass. -- Rock
builder (Zoöl.), any species of animal whose remains contribute to the
formation of rocks, especially the corals and Foraminifera. -- Rock
butter (Min.), native alum mixed with clay and oxide of iron, usually
in soft masses of a yellowish white color, occuring in cavities and
fissures in argillaceous slate. -- Rock candy, a form of candy
consisting of crystals of pure sugar which are very hard, whence the
name. -- Rock cavy. (Zoöl.) See Moco. -- Rock cod (Zoöl.) (a) A small,
often reddish or brown, variety of the cod found about rocks andledges.
(b) A California rockfish. -- Rock cook. (Zoöl.) (a) A European wrasse
(Centrolabrus exoletus). (b) A rockling. -- Rock cork (Min.), a variety
of asbestus the fibers of which are loosely interlaced. It resembles
cork in its texture. -- Rock crab (Zoöl.), any one of several species
of large crabs of the genus Cancer, as the two species of the New
England coast (C. irroratus and C. borealis). See Illust. under Cancer.
-- Rock cress (Bot.), a name of several plants of the cress kind found
on rocks, as Arabis petræa, A. lyrata, etc. -- Rock crystal (Min.),
limpid quartz. See Quartz, and under Crystal. -- Rock dove (Zoöl.), the
rock pigeon; -- called also rock doo. -- Rock drill, an implement for
drilling holes in rock; esp., a machine impelled by steam or compressed
air, for drilling holes for blasting, etc. -- Rock duck (Zoöl.), the
harlequin duck. -- Rock eel. (Zoöl.) See Gunnel. -- Rock goat (Zoöl.),
a wild goat, or ibex. -- Rock hopper (Zoöl.), a penguin of the genus
Catarractes. See under Penguin. -- Rock kangaroo. (Zoöl.) See Kangaroo,
and Petrogale. -- Rock lobster (Zoöl.), any one of several species of
large spinose lobsters of the genera Panulirus and Palinurus. They have
no large claws. Called also spiny lobster, and sea crayfish. -- Rock
meal (Min.), a light powdery variety of calcite occuring as an
efflorescence. -- Rock milk. (Min.) See Agaric mineral, under Agaric.
-- Rock moss, a kind of lichen; the cudbear. See Cudbear. -- Rock oil.
See Petroleum. -- Rock parrakeet (Zoöl.), a small Australian parrakeet
(Euphema petrophila), which nests in holes among the rocks of high
cliffs. Its general color is yellowish olive green; a frontal band and
the outer edge of the wing quills are deep blue, and the central tail
feathers bluish green. -- Rock pigeon (Zoöl.), the wild pigeon (Columba
livia) Of Europe and Asia, from which the domestic pigeon was derived.
See Illust. under Pigeon. -- Rock pipit. (Zoöl.) See the Note under
Pipit. -- Rock plover. (Zoöl.) (a) The black-bellied, or whistling,
plover. (b) The rock snipe. - - Rock ptarmigan (Zoöl.), an arctic
American ptarmigan (Lagopus rupestris), which in winter is white, with
the tail and lores black. In summer the males are grayish brown,
coarsely vermiculated with black, and have black patches on the back.
-- Rock rabbit (Zoöl.), the hyrax. See Cony, and Daman. -- Rock ruby
(Min.), a fine reddish variety of garnet. -- Rock salt (Min.), cloride
of sodium (common salt) occuring in rocklike masses in mines; mineral
salt; salt dug from the earth. In the United States this name is
sometimes given to salt in large crystals, formed by evaporation from
sea water in large basins or cavities. -- Rock seal (Zoöl.), the harbor
seal. See Seal. -- Rock shell (Zoöl.), any species of Murex, Purpura,
and allied genera. -- Rock snake (Zoöl.), any one of several large
pythons; as, the royal rock snake (Python regia) of Africa, and the
rock snake of India (P. molurus). The Australian rock snakes mostly
belong to the allied genus Morelia. -- Rock snipe (Zoöl.), the purple
sandpiper (Tringa maritima); -- called also rock bird, rock plover,
winter snipe. -- Rock soap (Min.), a kind of clay having a smooth,
greasy feel, and adhering to the tongue. -- Rock sparrow. (Zoöl.) (a)
Any one of several species of Old World sparrows of the genus Petronia,
as P. stulla, of Europe. (b) A North American sparrow (Pucæa ruficeps).
-- Rock tar, petroleum. -- Rock thrush (Zoöl.), any Old World thrush of
the genus Monticola, or Petrocossyphus; as, the European rock thrush
(M. saxatilis), and the blue rock thrush of India (M. cyaneus), in
which the male is blue throughout. -- Rock tripe (Bot.), a kind of
lichen (Umbilicaria Dillenii) growing on rocks in the northen parts of
America, and forming broad, flat, coriaceous, dark fuscous or blackish
expansions. It has been used as food in cases of extremity. -- Rock
trout (Zoöl.), any one of several species of marine food fishes of the
genus Hexagrammus, family Chiradæ, native of the North Pacific coasts;
-- called also sea trout, boregat, bodieron, and starling. -- Rock
warbler (Zoöl.), a small Australian singing bird (Origma rubricata)
which frequents rocky ravines and water courses; -- called also
cataract bird. -- Rock wren (Zoöl.), any one of several species of
wrens of the genus Salpinctes, native of the arid plains of Lower
California and Mexico.
Rock (?), v. t. [imp. & p. p. Rocked (?);p. pr. & vb. n. Rocking.] [AS.
roccian; akin to Dan. rokke to move, to snake; cf. Icel. rukkja to
pull, move, G. rücken to move, push, pull.] 1. To cause to sway
backward and forward, as a body resting on a support beneath; as, to
rock a cradle or chair; to cause to vibrate; to cause to reel or
totter.
A rising earthquake rocked the ground.
Dryden.
2. To move as in a cradle; hence, to put to sleep by rocking; to still;
to quiet. "Sleep rock thy brain." Shak.
Rock differs from shake, as denoting a slower, less violent, and more
uniform motion, or larger movements. It differs from swing, which
expresses a vibratory motion of something suspended.
Rock, v. i. 1. To move or be moved backward and forward; to be
violently agitated; to reel; to totter.
The rocking town Supplants their footsteps.
J. Philips .
2. To roll or saway backward and forward upon a support; as, to rock in
a rocking-chair.
Rock"a*way (?), [Probably from Rockaway beach, where it was used.]
Formerly, a light, low, four-wheeled carriage, with standing top, open
at the sides, but having waterproof curtains which could be let down
when occasion required; now, a somewhat similar, but heavier, carriage,
inclosed, except in front, and having a door at each side.
{ Rock"e*lay (?), Rock"lay (?) }, n. See Rokelay. [Scot.]
Rock"er, n. 1. One who rocks; specifically, one who rocks a cradle.
It was I, sir, said the rocker, who had the honor, some thirty
years since, to attend on your highness in your infancy.
Fuller.
2. One of the curving pieces of wood or metal on which a cradle, chair,
etc., rocks.
3. Any implement or machine working with a rocking motion, as a trough
mounted on rockers for separating gold dust from gravel, etc., by
agitation in water.