noun (n)

• no longer active; extinguished(noun.state)

  Example:
  The extinction of the volcano.
  

  source: wordnet30
• no longer in existence(noun.state)

  Example:
  The extinction of a species.
  

  Synonym:
  defunctness
  

  source: wordnet30
• the reduction of the intensity of radiation as a consequence of absorption and radiation(noun.process)

  source: wordnet30
• complete annihilation(noun.event)

  Example:
  They think a meteor cause the extinction of the dinosaurs.
  

  Synonym:
  extermination
  

  source: wordnet30
• a conditioning process in which the reinforcer is removed and a conditioned response becomes independent of the conditioned stimulus(noun.cognition)

  Synonym:
  experimental extinction
  

  source: wordnet30
• the act of extinguishing; causing to stop burning(noun.act)

  Example:
  The extinction of the lights.
  

  Synonym:
  extinguishing, quenching
  

  source: wordnet30
• 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.(noun)

  source: webster1913