noun (n)

• a process in which something passes by degrees to a different stage (especially a more advanced or mature stage)(noun.process)

  Example:
  The evolution of Greek civilization.
  

  Synonym:
  development
  Antonym:
  degeneration, devolution
  

  source: wordnet30
• (biology) the sequence of events involved in the evolutionary development of a species or taxonomic group of organisms(noun.process)

  Synonym:
  organic evolution, phylogenesis, phylogeny
  

  source: wordnet30
• The act of unfolding or unrolling; hence, in the process of growth; development; as, the evolution of a flower from a bud, or an animal from the egg.(noun)

  source: webster1913