[ik-stingk-shuh n]
See more synonyms for extinction on Thesaurus.com
  1. the act of extinguishing.
  2. the fact or condition of being extinguished or extinct.
  3. suppression; abolition; annihilation: the extinction of an army.
  4. Biology. the act or process of becoming extinct; a coming to an end or dying out: the extinction of a species.
  5. Psychology. the reduction or loss of a conditioned response as a result of the absence or withdrawal of reinforcement.
  6. Astronomy. the diminution in the intensity of starlight caused by absorption as it passes through the earth's atmosphere or through interstellar dust.
  7. 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.

Origin of extinction

1375–1425; late Middle English extinccio(u)n < Latin ex(s)tinctiōn- (stem of ex(s)tinctiō). See extinct, -ion
Related formsnon·ex·tinc·tion, nounpre·ex·tinc·tion, nounself-ex·tinc·tion, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for extinction

annihilation, elimination, destruction, obsolescence, death

Examples from the Web for extinction

Contemporary Examples of extinction

Historical Examples of extinction

British Dictionary definitions for extinction


  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 a process in which the frequency or intensity of a learned response is decreased as a result of reinforcement being withdrawnCompare habituation
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for extinction

early 15c., from Latin extinctionem/exstinctionem (nominative extinctio/exstinctio), noun of action from past participle stem of 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 by 1784.

Online Etymology Dictionary, © 2010 Douglas Harper

extinction in Medicine


  1. 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.absorbance
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

extinction in Science


  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 © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

extinction in Culture


The disappearance of a species from the Earth.


The fossil record tells us that 99.9 percent of all species that ever lived are now extinct.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.