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a process in which the frequency or intensity of a learned response is decreased as a result of reinforcement being withdrawn Compare habituation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

1. The fact of being extinct or the process of becoming extinct.

2. See more at background extinction mass 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.

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

Other Word Forms

• nonextinction noun
• preextinction noun
• self-extinction 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

Over a third of ray and shark species are threatened with extinction, largely due to overfishing, according to the International Union for the Conservation of Nature.

Read more on Barron's

The reforms, approved by parliament late Thursday night, will create an independent environmental regulator and stricter rules for land clearing -- a leading cause of native animal extinctions.

Read more on Barron's

Science fiction bursts at the seams with bizarre extinction scenarios, usually delivered from space, like the one that precipitates Carol’s irritating life turn.

Read more on Salon

They suggest that this protective feature may have helped ancient bryophytes, the plant group that includes mosses, move from water to land roughly 500 million years ago and survive repeated mass extinctions.

Read more on Science Daily

Thousands of species at risk of extinction in Wales have been revealed in a new study.

Read more on BBC

Related Words

• annihilation 
• destruction 
• elimination 
• obsolescence