Arabis petraea

Rock Rock, n. [OF. roke, F. roche; cf. Armor. roc'h, and AS. rocc.] 1. A large concreted mass of stony material; a large fixed stone or crag. See {Stone}. [1913 Webster]

Come one, come all! this rock shall fly From its firm base as soon as I. --Sir W. Scott. [1913 Webster]

2. (Geol.) Any natural deposit forming a part of the earth's crust, whether consolidated or not, including sand, earth, clay, etc., when in natural beds. [1913 Webster]

3. That which resembles a rock in firmness; a defense; a support; a refuge. [1913 Webster]

The Lord is my rock, and my fortress. --2 Sam. xxii. 2. [1913 Webster]

4. Fig.: Anything which causes a disaster or wreck resembling the wreck of a vessel upon a rock. [1913 Webster]

5. (Zo["o]l.) The striped bass. See under {Bass}. [1913 Webster]

Note: This word is frequently used in the formation of self-explaining compounds; as, rock-bound, rock-built, rock-ribbed, rock-roofed, and the like. [1913 Webster]

{Rock alum}. [Probably so called by confusion with F. roche a rock.] Same as {Roche alum}.

{Rock barnacle} (Zo["o]l.), a barnacle ({Balanus balanoides}) very abundant on rocks washed by tides.

{Rock bass}. (Zo["o]l.) (a) The stripped bass. See under {Bass}. (b) The goggle-eye. (c) The cabrilla. Other species are also locally called rock bass.

{Rock builder} (Zo["o]l.), 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}. (Zo["o]l.) See {Moco}.

{Rock cod} (Zo["o]l.) (a) A small, often reddish or brown, variety of the cod found about rocks andledges. (b) A California rockfish.

{Rock cook}. (Zo["o]l.) (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} (Zo["o]l.), any one of several species of large crabs of the genus {C}, as the two species of the New England coast ({Cancer irroratus} and {Cancer borealis}). See Illust. under {Cancer}.

{Rock cress} (Bot.), a name of several plants of the cress kind found on rocks, as {Arabis petr[ae]a}, {Arabis lyrata}, etc.

{Rock crystal} (Min.), limpid quartz. See {Quartz}, and under {Crystal}.

{Rock dove} (Zo["o]l.), 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} (Zo["o]l.), the harlequin duck.

{Rock eel}. (Zo["o]l.) See {Gunnel}.

{Rock goat} (Zo["o]l.), a wild goat, or ibex.

{Rock hopper} (Zo["o]l.), a penguin of the genus {Catarractes}. See under {Penguin}.

{Rock kangaroo}. (Zo["o]l.) See {Kangaroo}, and {Petrogale}.

{Rock lobster} (Zo["o]l.), 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} (Zo["o]l.), 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} (Zo["o]l.), the wild pigeon ({Columba livia}) Of Europe and Asia, from which the domestic pigeon was derived. See Illust. under {Pigeon}.

{Rock pipit}. (Zo["o]l.) See the Note under {Pipit}.

{Rock plover}. (Zo["o]l.) (a) The black-bellied, or whistling, plover. (b) The rock snipe.

{Rock ptarmigan} (Zo["o]l.), 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} (Zo["o]l.), 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} (Zo["o]l.), the harbor seal. See {Seal}.

{Rock shell} (Zo["o]l.), any species of Murex, Purpura, and allied genera.

{Rock snake} (Zo["o]l.), any one of several large pythons; as, the royal {rock snake} ({Python regia}) of Africa, and the {rock snake} of India ({Python molurus}). The Australian rock snakes mostly belong to the allied genus {Morelia}.

{Rock snipe} (Zo["o]l.), 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}. (Zo["o]l.) (a) Any one of several species of Old World sparrows of the genus {Petronia}, as {Petronia stulla}, of Europe. (b) A North American sparrow ({Puc[ae]a ruficeps}).

{Rock tar}, petroleum.

{Rock thrush} (Zo["o]l.), any Old World thrush of the genus {Monticola}, or {Petrocossyphus}; as, the European rock thrush ({Monticola saxatilis}), and the blue rock thrush of India ({Monticola 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} (Zo["o]l.), any one of several species of marine food fishes of the genus {Hexagrammus}, family {Chirad[ae]}, native of the North Pacific coasts; -- called also {sea trout}, {boregat}, {bodieron}, and {starling}.

{Rock warbler} (Zo["o]l.), a small Australian singing bird ({Origma rubricata}) which frequents rocky ravines and water courses; -- called also {cataract bird}.

{Rock wren} (Zo["o]l.), any one of several species of wrens of the genus {Salpinctes}, native of the arid plains of Lower California and Mexico. [1913 Webster]