noun (n)

• a state of surviving; remaining alive(noun.state)

  Synonym:
  endurance
  

  source: wordnet30
• a natural process resulting in the evolution of organisms best adapted to the environment(noun.process)

  Synonym:
  natural selection, selection, survival of the fittest
  

  source: wordnet30
• something that survives(noun.act)

  source: wordnet30
• A living or continuing longer than, or beyond the existence of, another person, thing, or event; an outliving.(noun)

  source: webster1913