Sand n.
 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent when wet.
    That finer matter, called sand, is no other than very small pebbles.   --Woodward.
 2. A single particle of such stone. [R.]
 3. The sand in the hourglass; hence, a moment or interval of time; the term or extent of one's life.
    The sands are numbered that make up my life.   --Shak.
 4. pl. Tracts of land consisting of sand, like the deserts of Arabia and Africa; also, extensive tracts of sand exposed by the ebb of the tide. “The Libyan sands.” --Milton. “The sands o' Dee.” --C. Kingsley.
 5. Courage; pluck; grit. [Slang]
 Sand badger Zool., the Japanese badger (Meles ankuma).
 Sand bag. (a) A bag filled with sand or earth, used for various purposes, as in fortification, for ballast, etc. (b) A long bag filled with sand, used as a club by assassins.
 Sand ball, soap mixed with sand, made into a ball for use at the toilet.
 Sand bath. (a) Chem. A vessel of hot sand in a laboratory, in which vessels that are to be heated are partially immersed. (b) A bath in which the body is immersed in hot sand.
 Sand bed, a thick layer of sand, whether deposited naturally or artificially; specifically, a thick layer of sand into which molten metal is run in casting, or from a reducing furnace.
 Sand birds Zool., a collective name for numerous species of limicoline birds, such as the sandpipers, plovers, tattlers, and many others; -- called also shore birds.
 Sand blast, a process of engraving and cutting glass and other hard substances by driving sand against them by a steam jet or otherwise; also, the apparatus used in the process.
 Sand box. (a) A box with a perforated top or cover, for sprinkling paper with sand. (b) A box carried on locomotives, from which sand runs on the rails in front of the driving wheel, to prevent slipping.
 Sand-box tree Bot., a tropical American tree (Hura crepitans). Its fruit is a depressed many-celled woody capsule which, when completely dry, bursts with a loud report and scatters the seeds. See Illust. of Regma.
 Sand bug Zool., an American anomuran crustacean (Hippa talpoidea) which burrows in sandy seabeaches. It is often used as bait by fishermen. See Illust. under Anomura.
 Sand canal Zool., a tubular vessel having a calcareous coating, and connecting the oral ambulacral ring with the madreporic tubercle. It appears to be excretory in function.
 Sand cock Zool., the redshank. [Prov. Eng.]
 Sand collar. Zool. Same as Sand saucer, below.
 Sand crab. Zool. (a) The lady crab. (b) A land crab, or ocypodian.
 Sand crack Far., a crack extending downward from the coronet, in the wall of a horse's hoof, which often causes lameness.
 Sand cricket Zool., any one of several species of large terrestrial crickets of the genus Stenophelmatus and allied genera, native of the sandy plains of the Western United States.
 Sand cusk Zool., any ophidioid fish. See Illust. under Ophidioid.
 Sand dab Zool., a small American flounder (Limanda ferruginea); -- called also rusty dab. The name is also applied locally to other allied species.
 Sand darter Zool., a small etheostomoid fish of the Ohio valley (Ammocrypta pellucida).
 Sand dollar Zool., any one of several species of small flat circular sea urchins, which live on sandy bottoms, especially Echinarachnius parma of the American coast.
 Sand drift, drifting sand; also, a mound or bank of drifted sand.
 Sand eel. Zool. (a) A lant, or launce. (b) A slender Pacific Ocean fish of the genus Gonorhynchus, having barbels about the mouth.
 Sand flag, sandstone which splits up into flagstones.
 Sand flea. Zool. (a) Any species of flea which inhabits, or breeds in, sandy places, especially the common dog flea. (b) The chigoe. (c) Any leaping amphipod crustacean; a beach flea, or orchestian. See Beach flea, under Beach.
 Sand flood, a vast body of sand borne along by the wind. --James Bruce.
 Sand fluke. Zool. (a) The sandnecker. (b) The European smooth dab (Pleuronectes microcephalus); -- called also kitt, marysole, smear dab, town dab.
 Sand fly Zool., any one of several species of small dipterous flies of the genus Simulium, abounding on sandy shores, especially Simulium nocivum of the United States. They are very troublesome on account of their biting habits. Called also no-see-um, punky, and midge.
 Sand gall. Geol. See Sand pipe, below.
 Sand grass Bot., any species of grass which grows in sand; especially, a tufted grass (Triplasis purpurea) with numerous bearded joints, and acid awl-shaped leaves, growing on the Atlantic coast.
 Sand grouse Zool., any one of many species of Old World birds belonging to the suborder Pterocletes, and resembling both grouse and pigeons. Called also rock grouse, rock pigeon, and ganga. They mostly belong to the genus Pterocles, as the common Indian species (Pterocles exustus). The large sand grouse (Pterocles arenarius), the painted sand grouse (Pterocles fasciatus), and the pintail sand grouse (Pterocles alchata) are also found in India. See Illust. under Pterocletes.
 Sand hill, a hill of sand; a dune.
 Sand-hill crane Zool., the American brown crane (Grus Mexicana).
 Sand hopper Zool., a beach flea; an orchestian.
 Sand hornet Zool., a sand wasp.
 Sand lark. Zool. (a) A small lark (Alaudala raytal), native of India. (b) A small sandpiper, or plover, as the ringneck, the sanderling, and the common European sandpiper. (c) The Australian red-capped dotterel (Aegialophilus ruficapillus); -- called also red-necked plover.
 Sand launce Zool., a lant, or launce.
 Sand lizard Zool., a common European lizard (Lacerta agilis).
 Sand martin Zool., the bank swallow.
 Sand mole Zool., the coast rat.
 Sand monitor Zool., a large Egyptian lizard (Monitor arenarius) which inhabits dry localities.
 Sand mouse Zool., the dunlin. [Prov. Eng.]
 Sand myrtle. Bot. See under Myrtle.
 Sand partridge Zool., either of two small Asiatic partridges of the genus Ammoperdix. The wings are long and the tarsus is spurless. One species (Ammoperdix Heeji) inhabits Palestine and Arabia. The other species (Ammoperdix Bonhami), inhabiting Central Asia, is called also seesee partridge, and teehoo.
 Sand picture, a picture made by putting sand of different colors on an adhesive surface.
 Sand pike. Zool. (a) The sauger. (b) The lizard fish.
 Sand pillar, a sand storm which takes the form of a whirling pillar in its progress in desert tracts like those of the Sahara and Mongolia.
 Sand pipe Geol., a tubular cavity, from a few inches to several feet in depth, occurring especially in calcareous rocks, and often filled with gravel, sand, etc.; -- called also sand gall.
 Sand pride Zool., a small British lamprey now considered to be the young of larger species; -- called also sand prey.
 Sand pump, in artesian well boring, a long, slender bucket with a valve at the bottom for raising sand from the well.
 Sand rat Zool., the pocket gopher.
 Sand rock, a rock made of cemented sand.
 Sand runner Zool., the turnstone.
 Sand saucer Zool., the mass of egg capsules, or oothecae, of any mollusk of the genus Natica and allied genera. It has the shape of a bottomless saucer, and is coated with fine sand; -- called also sand collar.
 Sand screw Zool., an amphipod crustacean (Lepidactylis arenarius), which burrows in the sandy seabeaches of Europe and America.
 Sand shark Zool., an American shark (Odontaspis littoralis) found on the sandy coasts of the Eastern United States; -- called also gray shark, and dogfish shark. See Illust. under Remora.
 Sand skink Zool., any one of several species of Old World lizards belonging to the genus Seps; as, the ocellated sand skink (Seps ocellatus) of Southern Europe.
 Sand skipper Zool., a beach flea, or orchestian.
 Sand smelt Zool., a silverside.
 Sand snake. Zool. (a) Any one of several species of harmless burrowing snakes of the genus Eryx, native of Southern Europe, Africa, and Asia, especially Eryx jaculus of India and Eryx Johnii, used by snake charmers. (b) Any innocuous South African snake of the genus Psammophis, especially Psammophis sibilans.
 Sand snipe Zool., the sandpiper.
 Sand star Zool., an ophiurioid starfish living on sandy sea bottoms; a brittle star.
 Sand storm, a cloud of sand driven violently by the wind.
 Sand sucker, the sandnecker.
 Sand swallow Zool., the bank swallow. See under Bank.
 Sand trap, Golf a shallow pit on a golf course having a layer of sand in it, usually located near a green, and designed to function as a hazard, due to the difficulty of hitting balls effectively from such a position.
 Sand tube, a tube made of sand. Especially: (a) A tube of vitrified sand, produced by a stroke of lightning; a fulgurite. (b) Zool. Any tube made of cemented sand. (c) Zool. In starfishes, a tube having calcareous particles in its wall, which connects the oral water tube with the madreporic plate.
 Sand viper. Zool. See Hognose snake.
 Sand wasp Zool., any one of numerous species of hymenopterous insects belonging to the families Pompilidae and Spheridae, which dig burrows in sand. The female provisions the nest with insects or spiders which she paralyzes by stinging, and which serve as food for her young.


 Screw n.
 1. A cylinder, or a cylindrical perforation, having a continuous rib, called the thread, winding round it spirally at a constant inclination, so as to leave a continuous spiral groove between one turn and the next, -- used chiefly for producing, when revolved, motion or pressure in the direction of its axis, by the sliding of the threads of the cylinder in the grooves between the threads of the perforation adapted to it, the former being distinguished as the external, or male screw, or, more usually the screw; the latter as the internal, or female screw, or, more usually, the nut.
 Note: ☞ The screw, as a mechanical power, is a modification of the inclined plane, and may be regarded as a right-angled triangle wrapped round a cylinder, the hypotenuse of the marking the spiral thread of the screw, its base equaling the circumference of the cylinder, and its height the pitch of the thread.
 2. Specifically, a kind of nail with a spiral thread and a head with a nick to receive the end of the screw-driver. Screws are much used to hold together pieces of wood or to fasten something; -- called also wood screws, and screw nails. See also Screw bolt, below.
 3. Anything shaped or acting like a screw; esp., a form of wheel for propelling steam vessels. It is placed at the stern, and furnished with blades having helicoidal surfaces to act against the water in the manner of a screw. See Screw propeller, below.
 4. A steam vesel propelled by a screw instead of wheels; a screw steamer; a propeller.
 5. An extortioner; a sharp bargainer; a skinflint; a niggard.
 6. An instructor who examines with great or unnecessary severity; also, a searching or strict examination of a student by an instructor. [Cant, American Colleges]
 7. A small packet of tobacco. [Slang]
 8. An unsound or worn-out horse, useful as a hack, and commonly of good appearance.
 9. Math. A straight line in space with which a definite linear magnitude termed the pitch is associated (cf. 5th Pitch, 10 (b)). It is used to express the displacement of a rigid body, which may always be made to consist of a rotation about an axis combined with a translation parallel to that axis.
 10. Zool. An amphipod crustacean; as, the skeleton screw (Caprella). See Sand screw, under Sand.
 Archimedes screw, Compound screw, Foot screw, etc. See under Archimedes, Compound, Foot, etc.
 A screw loose, something out of order, so that work is not done smoothly; as, there is a screw loose somewhere. --H. Martineau.
 Endless screw, or perpetual screw, a screw used to give motion to a toothed wheel by the action of its threads between the teeth of the wheel; -- called also a worm.
 Lag screw. See under Lag.
 Micrometer screw, a screw with fine threads, used for the measurement of very small spaces.
 Right and left screw, a screw having threads upon the opposite ends which wind in opposite directions.
 Screw alley. See Shaft alley, under Shaft.
 Screw bean. Bot. (a) The curious spirally coiled pod of a leguminous tree (Prosopis pubescens) growing from Texas to California. It is used for fodder, and ground into meal by the Indians. (b) The tree itself. Its heavy hard wood is used for fuel, for fencing, and for railroad ties.
 Screw bolt, a bolt having a screw thread on its shank, in distinction from a key bolt. See 1st Bolt, 3.
 Screw box, a device, resembling a die, for cutting the thread on a wooden screw.
 Screw dock. See under Dock.
 Screw engine, a marine engine for driving a screw propeller.
 Screw gear. See Spiral gear, under Spiral.
 Screw jack. Same as Jackscrew.
 Screw key, a wrench for turning a screw or nut; a spanner wrench.
 Screw machine. (a) One of a series of machines employed in the manufacture of wood screws. (b) A machine tool resembling a lathe, having a number of cutting tools that can be caused to act on the work successively, for making screws and other turned pieces from metal rods.
 Screw pine Bot., any plant of the endogenous genus Pandanus, of which there are about fifty species, natives of tropical lands from Africa to Polynesia; -- named from the spiral arrangement of the pineapple-like leaves.
 Screw plate, a device for cutting threads on small screws, consisting of a thin steel plate having a series of perforations with internal screws forming dies.
 Screw press, a press in which pressure is exerted by means of a screw.
 Screw propeller, a screw or spiral bladed wheel, used in the propulsion of steam vessels; also, a steam vessel propelled by a screw.
 Screw shell Zool., a long, slender, spiral gastropod shell, especially of the genus Turritella and allied genera. See Turritella.
 Screw steamer, a steamship propelled by a screw.
 Screw thread, the spiral rib which forms a screw.
 Screw stone Paleon., the fossil stem of an encrinite.
 Screw tree Bot., any plant of the genus Helicteres, consisting of about thirty species of tropical shrubs, with simple leaves and spirally twisted, five-celled capsules; -- also called twisted-horn, and twisty.
 Screw valve, a stop valve which is opened or closed by a screw.
 Screw worm Zool., the larva of an American fly (Compsomyia macellaria), allied to the blowflies, which sometimes deposits its eggs in the nostrils, or about wounds, in man and other animals, with fatal results.
 Screw wrench. (a) A wrench for turning a screw. (b) A wrench with an adjustable jaw that is moved by a screw.
 To put the screws on or To put the screw on, to use pressure upon, as for the purpose of extortion; to coerce.
 To put under the screw or To put under the screws, to subject to pressure; to force.
 Wood screw, a metal screw with a sharp thread of coarse pitch, adapted to holding fast in wood. See Illust. of Wood screw, under Wood.