noun (n)

• a document giving an official instruction or command(noun.communication)

  Synonym:
  authorisation, mandate
  

  source: wordnet30
• the power or right to give orders or make decisions(noun.attribute)

  Example:
  Deputies are given authorization to make arrests.
  

  Synonym:
  authorisation, authority, dominance, potency, say-so
  

  source: wordnet30
• official permission or approval(noun.attribute)

  Synonym:
  authorisation, authority, sanction
  

  source: wordnet30
• the act of conferring legality or sanction or formal warrant(noun.act)

  Synonym:
  authorisation, empowerment
  

  source: wordnet30
• The act of giving authority or legal power; establishment by authority; sanction or warrant.(noun)

  source: webster1913