noun (n)

• personal knowledge or information about someone or something(noun.cognition)

  Synonym:
  acquaintance, conversance, conversancy
  

  source: wordnet30
• usualness by virtue of being familiar or well known(noun.attribute)

  Antonym:
  strangeness, unfamiliarity
  

  source: wordnet30
• close or warm friendship(noun.attribute)

  Synonym:
  closeness, intimacy
  

  source: wordnet30
• a casual manner(noun.attribute)

  Synonym:
  casualness
  

  source: wordnet30
• an act of undue intimacy(noun.act)

  Synonym:
  impropriety, indecorum, liberty
  

  source: wordnet30
• The state of being familiar; intimate and frequent converse, or association; unconstrained intercourse; freedom from ceremony and constraint; intimacy; as, to live in remarkable familiarity.(noun)

  source: webster1913