| rock | 1. A large concreted mass of stony material; a large fixed stone or crag. See Stone. "Come one, come all! this rock shall fly From its firm base as soon as I." (Sir W. Scott) 2. <geology> Any natural deposit forming a part of the earth's crust, whether consolidated or not, including sand, earth, clay, etc, when in natural beds. 3. That which resembles a rock in firmness; a defense; a support; a refuge. "The Lord is my rock, and my fortress." (2 Sam. Xxii. 2) 4. Anything which causes a disaster or wreck resembling the wreck of a vessel upon a rock. 5. <zoology> The striped bass. See Bass. 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, any one of several species of wrens of the genus Salpinctes, native of the arid plains of Lower California and Mexico. Origin: OF. Roke, F. Roche; cf. Armor. Roc'h, and AS. Rocc. Source: Websters Dictionary (01 Mar 1998) |
|---|---|
| rock oil | Rock oil, mineral oil, or natural oil, a dark brown or greenish inflammable liquid, which, at certain points, exists in the upper strata of the earth, from whence it is pumped, or forced by pressure of the gas attending it. It consists of a complex mixture of various hydrocarbons, largely of the methane series, but may vary much in appearance, composition, and properties. It is refined by distillation, and the products include kerosene, benzine, gasoline, paraffin, etc. Petroleum spirit, a volatile liquid obtained in the distillation of crude petroleum at a temperature of 170 deg Fahr, or below. The term is rather loosely applied to a considerable range of products, including benzine and ligroin. The terms petroleum ether, and naphtha, are sometimes applied to the still more volatile products, including rhigolene, gasoline, cymogene, etc. Origin: NL, fr. L. Petra a rock + oleum oil: cf. F. Petrole. Cf. Petrify, and Oil. Source: Websters Dictionary (01 Mar 1998) |
| rock shaft | <machinery> A shaft that oscillates on its journals, instead of revolving, usually carrying levers by means of which it receives and communicates reciprocating motion, as in the valve gear of some steam engines. Synonym: rocker, rocking shaft, and way shaft. Origin: Cf. Rock, v. I. Source: Websters Dictionary (01 Mar 1998) |
| rock staff | An oscillating bar in a machine, as the lever of the bellows of a forge. Origin: Cf. Rock. Source: Websters Dictionary (01 Mar 1998) |
| rocker | 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. 4. A play horse on rockers; a rocking-horse. 5. A chair mounted on rockers; a rocking-chair. 6. A skate with a curved blade, somewhat resembling in shape the rocker of a cradle. 7. <machinery> Same as Rock shaft. <machinery> Rocker arm, an arm borne by a rock shaft. Source: Websters Dictionary (01 Mar 1998) |
| rockery | <botany> A mound formed of fragments of rock, earth, etc, and set with plants. Source: Websters Dictionary (01 Mar 1998) |
| rocket | 1. An artificial firework consisting of a cylindrical case of paper or metal filled with a composition of combustible ingredients, as niter, charcoal, and sulphur, and fastened to a guiding stick. The rocket is projected through the air by the force arising from the expansion of the gases liberated by combustion of the composition. Rockets are used as projectiles for various purposes, for signals, and also for pyrotechnic display. 2. A blunt lance head used in the joust. Congreve rocket, a powerful form of rocket for use in war, invented by Sir William Congreve. It may be used either in the field or for bombardment; in the former case, it is armed with shells or case shot; in the latter, with a combustible material inclosed in a metallic case, which is inextinguishable when kindled, and scatters its fire on every side. Origin: It. Rocchetta, fr. Rocca a distaff, of German origin. Named from the resemblance in shape to a distaff. See Rock a distaff. <botany> A cruciferous plant (Eruca sativa) sometimes eaten in Europe as a salad. <botany> A common cruciferous weed with yellow flowers (Barbarea vulgaris). Origin: F. Roquette (cf. Sp. Ruqueta, It ruchetta), fr. L. Eruca. Source: Websters Dictionary (01 Mar 1998) |
| rocket immunoelectrophoresis | A quantitative method for serum proteins which involves electrophoresis of antigen into a gel containing antibody; the technique is restricted to detection of antigens that move to the positive pole on electrophoresis. See: electroimmunodiffusion. Two-dimensional immunoelectrophoresis, a combination of conventional electrophoretic separation and electroimmunodiffusion; electrophoresis is first carried out, then the electrophoretic strip is placed on a second slide and an antibody-containing agarose solution is allowed to solidify adjacent to it; electrophoresis is then performed at right angles to the original separation. Synonym: crossed immunoelectrophoresis. (05 Mar 2000) |
| rockfish | <zoology> Any one of several California scorpaenoid food fishes of the genus Sebastichthys, as the red rockfish (S. Ruber). They are among the most important of California market fishes. Called also rock cod, and garrupa. The striped bass. See Bass. Any one of several species of Florida and Bermuda groupers of the genus Epinephelus. An American fresh water darter; the log perch. The term is locally applied to various other fishes. Source: Websters Dictionary (01 Mar 1998) |
| rockling | <zoology> Any species of small marine fishes of the genera Onos and Rhinonemus (formerly Motella), allied to the cod. They have three or four barbels. Source: Websters Dictionary (01 Mar 1998) |
| rockrose | <botany> A name given to any species of the genus Helianthemum, low shrubs or herbs with yellow flowers, especially the European H. Vulgare and the American frostweed, H. Canadense. Cretan rockrose, a related shrub (Cistus Creticus), one of the plants yielding the fragrant gum called ladanum. Source: Websters Dictionary (01 Mar 1998) |
| rocksucker | <zoology> A lamprey. Source: Websters Dictionary (01 Mar 1998) |
| rockweed | <botany> Any coarse seaweed growing on sea-washed rocks, especially Fucus. Source: Websters Dictionary (01 Mar 1998) |
| rockwood | <chemical> Ligniform asbestus; also, fossil wood. Source: Websters Dictionary (01 Mar 1998) |
| rockwork | 1. Stonework in which the surface is left broken and rough. 2. <botany> A rockery. Source: Websters Dictionary (01 Mar 1998) |
| bed rock | <chemical> The solid rock underlying superficial formations. Also Source: Websters Dictionary (01 Mar 1998) |
|---|