3. Hence: To practice extortion upon; to oppress by unreasonable or extortionate exactions. Our country landlords, by unmeasureable screwing and racking their tenants, have already reduced the miserable people to a worse condition than the peasants in France. (swift)
5. To examine rigidly, as a student; to subject to a severe examination. To screw out, to press out; to extort. To screw up, to force; to bring by violent pressure. To screw in, to force in by turning or twisting.
Origin: Screwed; Screwing.
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.
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; especially, 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.
9. (Science: mathematics) A straight line in space with which a definite linear magnitude termed the pitch is associated (cf. 5th Pitch, 10). 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. (Science: zoology) An amphipod crustacean; as, the skeleton screw (Caprel 1000 la). See sand screw, under Sand. Archimedes screw, compound screw, foot screw, etc. See 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. Endless, 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 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. Screw bean.
(Science: botany) 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 wrench for turning a screw. A wrench with an adjustable jaw that is moved by a screw. To put the screw, or screws, on, to use pressure upon, as for the purpose of extortion; to coerce. To put under the screw or screws, to subject to presure; to force. Wood screw, a metal screw with a sharp thread of coarse pitch, adapted to holding fast in wood.
Origin: OE. Scrue, OF. Escroue, escroe, female screw, F. Ecrou, L. Scrobis a ditch, trench, in LL, the hole made by swine in rooting; cf. D. Schroef a screw, G. Schraube, Icel. Skrfa.