[ ik-stingk-shuhn ]
See synonyms for extinction on Thesaurus.com
  1. the act of extinguishing.

  2. the fact or condition of being extinguished or extinct.

  1. suppression; abolition; annihilation: the extinction of an army.

  2. Biology. the act or process of becoming extinct; a coming to an end or dying out: the extinction of a species.

  3. Psychology. the reduction or loss of a conditioned response as a result of the absence or withdrawal of reinforcement.

  4. Astronomy. the diminution in the intensity of starlight caused by absorption as it passes through the earth's atmosphere or through interstellar dust.

  5. 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

Other words from extinction

  • non·ex·tinc·tion, noun
  • pre·ex·tinc·tion, noun
  • self-ex·tinc·tion, noun

Words Nearby extinction

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use extinction in a sentence

British Dictionary definitions for 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

  1. complete destruction; annihilation

  2. physics reduction of the intensity of radiation as a result of absorption or scattering by matter

  3. 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

  4. psychol a process in which the frequency or intensity of a learned response is decreased as a result of reinforcement being withdrawn: Compare habituation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

Scientific definitions for extinction


[ ĭk-stĭngkshən ]

  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.

Cultural definitions for extinction


The disappearance of a species from the Earth.

Notes for extinction

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.