noun (n)

• the state or quality of being recognized or acknowledged(noun.state)

  Synonym:
  acknowledgement, recognition
  

  source: wordnet30
• a short note recognizing a source of information or of a quoted passage(noun.communication)

  Example:
  The acknowledgments are usually printed at the front of a book.
  

  Synonym:
  citation, cite, credit, mention, quotation, reference
  

  source: wordnet30
• a statement acknowledging something or someone(noun.communication)

  Example:
  She must have seen him but she gave no sign of acknowledgment.
  The preface contained an acknowledgment of those who had helped her.
  

  Synonym:
  acknowledgement
  

  source: wordnet30
• The act of acknowledging; admission; avowal; owning; confession.(noun)

  source: webster1913