WordWeb Online

1. No longer active; extinguished
   "the extinction of the volcano"
    
2. No longer in existence
   "the extinction of a species";
   - defunctness
    
3. (physics) reduction of the intensity of radiation as a consequence of absorption or scattering
    
4. Complete annihilation
   "they think a meteor caused the extinction of the dinosaurs";
   - extermination
    
5. A conditioning process in which the reinforcer is removed and a conditioned response becomes independent of the conditioned stimulus
   - experimental extinction
    
6. The act of extinguishing; causing to stop burning
   "the extinction of the lights";
   - quenching

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