noun (n)

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

  Synonym:
  conversance, conversancy, familiarity
  

  source: wordnet30
• a relationship less intimate than friendship(noun.state)

  Synonym:
  acquaintanceship
  

  source: wordnet30
• a person with whom you are acquainted(noun.person)

  Example:
  I have trouble remembering the names of all my acquaintances.
  

  Synonym:
  friend
  Antonym:
  stranger
  

  source: wordnet30
• A state of being acquainted, or of having intimate, or more than slight or superficial, knowledge; personal knowledge gained by intercourse short of that of friendship or intimacy; as, I know the man; but have no acquaintance with him.(noun)

  source: webster1913