evolution

a process in which something passes by degrees to a different stage (especially a more advanced or mature stage); "the development of his ideas took many years"; "the evolution of Greek civilization"; "the slow development of her skill as a writer"

Source: WordNet® 3.1, Princeton University — "WordNet Copyright 2011 by Princeton University. All rights reserved." Used under WordNet's license terms. See methodology for full licensing detail. Word validity for game play may differ from any official game dictionary.