| levee | A natural or manmade feature of the landscape that restricts movement of water into or through an area. (09 Oct 1997) |
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| LeVeen shunt | A plastic tube used to transport ascitic fluid from the abdomen, via a jugular vein, to the superior vena cava. (05 Mar 2000) |
| LeVeen, Harry | <person> U.S. Surgeon, *1914. See: LeVeen shunt. (05 Mar 2000) |
| level of aspiration | <psychology> The degree or quality of performance (exhibited in a testing situation) which an individual desires to attain or feels he can achieve. (05 Mar 2000) |
| levelised life-cycle cost | The present value of the cost of a resource, including capital, financing and operating costs, expressed as a stream of equal annual payments. This stream of payments can be converted to a unit cost of energy by dividing the annual payment amount by the annual kilowatt-hours produced or saved. By levelizing costs, resources with different lifetimes and generating capabilities can be compared. (05 Dec 1998) |
| Leventhal, Michael | <person> U.S. Obstetrician-gynecologist, 1901-1971. See: Stein-Leventhal syndrome. (05 Mar 2000) |
| lever | 1. <mechanics> A rigid piece which is capable of turning about one point, or axis (the fulcrum), and in which are two or more other points where forces are applied; used for transmitting and modifying force and motion. Specif, a bar of metal, wood, or other rigid substance, used to exert a pressure, or sustain a weight, at one point of its length, by receiving a force or power at a second, and turning at a third on a fixed point called a fulcrum. It is usually named as the first of the six mechanical powers, and is three kinds, according as either the fulcrum F, the weight W, or the power P. Respectively, is situated between the other two, as in the figures. 2. <machinery> A bar, as a capstan bar, applied to a rotatory piece to turn it. An arm on a rock shaft, to give motion to the shaft or to obtain motion from it. Compound lever, a machine consisting of two or more levers acting upon each other. Lever escapement. See Escapement. Lever jack. See Jack. Lever watch, a watch having a vibrating lever to connect the action of the escape wheel with that of the balance. Universal lever, a machine formed by a combination of a lever with the wheel and axle, in such a manner as to convert the reciprocating motion of the lever into a continued rectilinear motion of some body to which the power is applied. Origin: OE. Levour, OF. Leveor, prop, a lifter, fr. F. Lever to raise, L. Levare; akin to levis light in weight, E. Levity, and perh. To E. Light not heavy: cf. F. Levier. Cf. Alleviate, Elevate, Leaven, Legerdemain, Levy. Source: Websters Dictionary (01 Mar 1998) |
| leverage | The action of a lever; mechanical advantage gained by the lever. <mechanics> Leverage of a couple, the perpendicular distance between the lines of action of two forces which act in parallel and opposite directions. Leverage of a force, the perpendicular distance from the line in which a force acts upon a body to a point about which the body may be supposed to turn. Source: Websters Dictionary (01 Mar 1998) |
| leveret | <zoology> A hare in the first year of its age. Origin: F. Levraut, dim. Of lievre hare, L. Lepus. Cf. Leporine. Source: Websters Dictionary (01 Mar 1998) |
| leverwood | <botany> The American hop hornbeam (Ostrya Virginica), a small tree with very tough wood. Source: Websters Dictionary (01 Mar 1998) |
| levesel | A leafy shelter; a place covered with foliage. "Behind the mill, under a levesel." (Chaucer) Origin: AS. Leaf a leaf + sael, sel, a room, a hall. Source: Websters Dictionary (01 Mar 1998) |
| Levi, E Leopold | <person> French endocrinologist, 1868-1933. See: dominantly inherited Levi's disease, Lorain-Levi dwarfism, Lorain-Levi infantilism, Lorain-Levi syndrome. (05 Mar 2000) |
| Levin tube | A tube introduced through the nose into the upper alimentary canal, to facilitate intestinal decompression. (05 Mar 2000) |
| Levin, Abraham | <person> U.S. Physician, 1880-1940. See: Levin tube. (05 Mar 2000) |
| Levin, Max | <person> U.S. Neurologist, *1901. See: Kleine-Levin syndrome. (05 Mar 2000) |