noun (n)

• an occurrence that involves the production of a union(noun.event)

  Synonym:
  fusion, merger
  

  source: wordnet30
• the state of being joined or united or linked(noun.state)

  Synonym:
  union
  Antonym:
  separation
  

  source: wordnet30
• the act of making or becoming a single unit(noun.act)

  Example:
  He looked forward to the unification of his family for the holidays.
  

  Synonym:
  conjugation, jointure, union, uniting
  Antonym:
  disunion
  

  source: wordnet30
• The act of unifying, or the state of being unified.(noun)

  source: webster1913