1. The dying out or disappearance of a species, family, or larger group of organisms
   "the extinction of a species"
    
2. The state of no longer existing, functioning, or being active or in use
   "the extinction of the volcano"
    
3. Complete annihilation
   "they think a meteor caused the extinction of the dinosaurs";
   - extermination
    
4. The act of extinguishing; causing to stop burning
   "the extinction of the lights"
    
5. (physics) reduction of the intensity of radiation as a consequence of absorption or scattering
   "The extinction of starlight by interstellar dust makes distant objects appear dimmer"
    
6. A conditioning process in which the reinforcer is removed and a conditioned response becomes independent of the conditioned stimulus
   "The researchers studied experimental extinction by no longer providing food when the bell rang";
   - experimental extinction

Derived forms: extinctions

See also: extinct

Type of: action, activity, annihilation, conclusion, conditioning, death, disintegration, ending, inaction, inactiveness, inactivity, natural action, natural process, termination

Encyclopedia: Extinction