extinction

[ ik-stingk-shuhn ]

noun

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 extinction angle at which plane-polarized light is absorbed by the polarizer.

extinction

/ ɪkˈstɪŋkʃən /

noun

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a process in which the frequency or intensity of a learned response is decreased as a result of reinforcement being withdrawn Compare habituation

extinction

/ ĭk-stĭngk′shən /

1. The fact of being extinct or the process of becoming extinct.
2. See more at background extinction
3. A progressive decrease in the strength of a conditioned response, often resulting in its elimination, because of withdrawal of a specific stimulus.

extinction

1. The disappearance of a species from the Earth .

Notes

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

Other Words From

• nonex·tinction noun
• preex·tinction noun
• self-ex·tinction noun

Word History and Origins

Origin of extinction¹

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

Example Sentences

Navaornis lived approximately 80 million years ago in what is now Brazil, before the mass extinction event that killed all non-avian dinosaurs.

From BBC

In the early 1900s, the conservationist and anthropologist Madison Grant, who helped establish Glacier National Park and the Bronx Zoo, wrote pseudoscientific tomes about the coming extinction of white people.

From Salon

White people are an endangered breed, fighting to delay their extinction.

From Salon

A report this week found that 44% of corals living in warm waters are threatened with extinction, according to the International Union for the Conservation of Nature.

From BBC

But some of the bird's unique evolutionary traits are clashing with human interventions, making it vulnerable to extinction.

From BBC

Related Words

• annihilation
• destruction
• elimination
• obsolescence