extinction

Extinction is defined as the act of ending the existence of a plant or animal.

(noun)

An example of extinction is killing off the last of a rare bird.

The definition of extinction is putting something out.

(noun)

An example of extinction is putting out a fire at a campsite.

See extinction in Webster's New World College Dictionary

noun

a putting out or being put out, as of a fire
a destroying or being destroyed; annihilation; abolition
the fact or state of being or becoming extinct; dying out, as a species of animal
Physiol., Psychol. the weakening and disappearance of a conditioned response that is no longer being reinforced

Origin: ME extinccioun < L exstinctio < exstinctus: see extinct

See extinction in American Heritage Dictionary 4

noun

a. The act of extinguishing.
b. The condition of being extinguished.
The fact of being extinct or the process of becoming extinct: “The most effective agent in the extinction of species is the pressure of other species” (Alfred R. Wallace).
Psychology A reduction or a loss in the strength or rate of a conditioned response when the unconditioned stimulus or reinforcement is withheld.
Physiology A gradual decrease in the excitability of a nerve to a previously adequate stimulus, usually resulting in total loss of excitability.