noun, plural lenses.
a piece of transparent substance, usually glass, having two opposite surfaces either both curved or one curved and one plane, used in an optical device in changing the convergence of light rays, as for magnification, or in correcting defects of vision.
a combination of such pieces.
some analogous device, as for affecting sound waves, electromagnetic radiation, or streams of electrons.
Geology. a body of rock or ore that is thick in the middle and thinner toward the edges, similar in shape to a biconvex lens.
verb (used with object)
Movies. to film (a motion picture).

1685–95; < Neo-Latin, special use of Latin lēns a lentil (from its shape); see lentil

lensless, adjective
lenslike, adjective
unlensed, adjective
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a male given name, form of Leonard.
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Based on the Random House Dictionary, © Random House, Inc. 2014.
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World English Dictionary
lens (lɛnz)
1.  a piece of glass or other transparent material, used to converge or diverge transmitted light and form optical images
2.  Also called: compound lens a combination of such lenses for forming images or concentrating a beam of light
3.  See electron lens a device that diverges or converges a beam of electromagnetic radiation, sound, or particles
4.  anatomy See crystalline lens
Related: lenticular
[C17: from Latin lēns lentil, referring to the similarity of a lens to the shape of a lentil]

Lens (lenz, French lɑ̃)
an industrial town in N France, in the Pas de Calais department; badly damaged in both World Wars. Pop: 36 206 (1999)

Collins English Dictionary - Complete & Unabridged 10th Edition
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Word Origin & History

1690s, from L. lens (gen. lentis) "lentil," on analogy of the double-convex shape. See lentil.
Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage
Medical Dictionary

lens (lěnz)
n. pl. lens·es

  1. A ground or molded piece of glass, plastic, or other transparent material with opposite surfaces either or both of which are curved, by means of which light rays are refracted so that they converge or diverge to form an image.

  2. A transparent, biconvex body of the eye between the iris and the vitreous humor that focuses light rays entering through the pupil to form an image on the retina.

lensed adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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American Heritage
Science Dictionary
lens   (lěnz)  Pronunciation Key 

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  1. A transparent structure behind the iris of the eye that focuses light entering the eye on the retina.

    1. A piece of glass or plastic shaped so as to focus or spread light rays that pass through it, often for the purpose of forming an image.

    2. A combination of two or more such lenses, as in a camera or telescope. Also called compound lens.

  2. A device that causes radiation to converge or diverge by an action analogous to that of an optical lens. The system of electric fields used to focus electron beams in electron microscopes is an example of a lens.

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Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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American Heritage
Cultural Dictionary

lens definition

A piece of transparent material, such as glass, that forms an image from the rays of light passing through it. (See focal length, refraction, and telescope.)

lens definition

A clear, almost spherical structure located just behind the pupil of the eye. The lens focuses waves of light on the retina.

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Encyclopedia Britannica


industrial town, Pas-de-Calais departement, Nord-Pas-de-Calais region, northern France, southwest of Lille. It was the chief urban centre of the Pas-de-Calais coal basin. Since the demise of coal mining in the 1980s, a wide range of new industries and services has been developed in Lens. These include companies manufacturing wires and cables, paper, metals, glass, frozen foods, and chemicals, as well as firms specializing in packaging and transport. Lens is also a commercial and administrative centre, and it is the site of a branch of the University of Artois. The town, which was completely destroyed in World War I, was damaged again in World War II. Pop. (1999) town, 36,206; (2004 est.) 35,200

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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Example sentences for lens
They are characterized by seeing the world through an agricultural lens.
No radiation remains, just like no light remains in a lens.
It has primitive eyes compared to other cephalopods, mostly because they have no lens.
Some multipurpose solutions are not effective at disinfecting acanthamoeba from the lens.
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