extinction angle


the act of extinguishing.
the fact or condition of being extinguished or extinct.
suppression; abolition; annihilation: the extinction of an army.
Biology. the act or process of becoming extinct; a coming to an end or dying out: the extinction of a species.
Psychology. the reduction or loss of a conditioned response as a result of the absence or withdrawal of reinforcement.
Astronomy. the diminution in the intensity of starlight caused by absorption as it passes through the earth's atmosphere or through interstellar dust.
Crystallography, Optics. the darkness that results from rotation of a thin section to an angle (extinction angle) at which plane-polarized light is absorbed by the polarizer.

1375–1425; late Middle English extinccio(u)n < Latin ex(s)tinctiōn- (stem of ex(s)tinctiō). See extinct, -ion

nonextinction, noun
preextinction, noun
self-extinction, noun
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Based on the Random House Dictionary, © Random House, Inc. 2014.
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World English Dictionary
extinction (ɪkˈstɪŋkʃən)
1.  the act of making extinct or the state of being extinct
2.  the act of extinguishing or the state of being extinguished
3.  complete destruction; annihilation
4.  physics reduction of the intensity of radiation as a result of absorption or scattering by matter
5.  astronomy the dimming of light from a celestial body as it passes through an absorbing or scattering medium, such as the earth's atmosphere or interstellar dust
6.  psychol Compare habituation a process in which the frequency or intensity of a learned response is decreased as a result of reinforcement being withdrawn

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

late 15c., from L. extinctionem/exstinctionem, noun of action from extinguere/exstinguere (see extinguish). Originally of fires, lights; figurative use, of wiping out a material thing (a debt, a person, a family, etc.) from early 17c.; of species from 1880.
Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage
Medical Dictionary

extinction ex·tinc·tion (ĭk-stĭngk'shən)
Progressive reduction in the strength of the conditioned response in successive conditioning trials during which only the conditioned stimulus is presented and the unconditioned stimulus is omitted. See absorbance.

The American Heritage® Stedman's Medical Dictionary
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American Heritage
Science Dictionary
extinction  [%PREMIUM_LINK%]     (ĭk-stĭngk'shən)  Pronunciation Key 
  1. The fact of being extinct or the process of becoming extinct. See more at background extinction, mass extinction.

  2. A progressive decrease in the strength of a conditioned response, often resulting in its elimination, because of withdrawal of a specific stimulus.

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

extinction definition

The disappearance of a species from the Earth.

Note: The fossil record tells us that 99.9 percent of all species that ever lived are now extinct.
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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