noun (n)

• the act of relieving ills and changing for the better(noun.act)

  Synonym:
  amelioration, betterment
  

  source: wordnet30
• a condition superior to an earlier condition(noun.state)

  Synonym:
  improvement
  Antonym:
  declination, decline
  

  source: wordnet30
• the linguistic process in which over a period of time a word grows more positive in connotation or more elevated in meaning(noun.process)

  source: wordnet30
• The act or operation of meliorating, or the state of being meliorated; improvement.(noun)

  source: webster1913