The act of extinguishing or making extinct; a putting an end to; the act of putting out or destroying light, fire, life, activity, influence, etc.
- The act of extinguishing.
- 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.