noun (n)

• agreement of results or opinions(noun.communication)

  Synonym:
  concurrency
  

  source: wordnet30
• acting together, as agents or circumstances or events(noun.act)

  source: wordnet30
• a state of cooperation(noun.state)

  Synonym:
  meeting of minds
  

  source: wordnet30
• the temporal property of two things happening at the same time(noun.attribute)

  Synonym:
  co-occurrence, coincidence, conjunction
  

  source: wordnet30
• The act of concurring; a meeting or coming together; union; conjunction; combination.(noun)

  source: webster1913