Extinction

[ik-stingk-shuh n] /ɪkˈstɪŋk ʃən/

noun
1.
the act of .
2.
the fact or condition of being or .
3.
suppression; abolition; annihilation:
the extinction of an army.
4.
Biology. the act or process of becoming ; 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.
/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a process in which the frequency or intensity of a learned response is decreased as a result of reinforcement being withdrawn Compare habituation
n.

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.

extinction ex·tinc·tion (ĭk-stĭngk’shən)
n.
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.
extinction
(ĭk-stĭngk’shən)

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.