What is the meaning of authorisation?

noun

• A document giving an official instruction or command.
  • synonyms: mandate, authorization
• The power or right to give orders or make decisions.
  • usage: "he has the authority to issue warrants"; "deputies are given authorization to make arrests"; "a place of potency in the state"
  • synonyms: authority, authorization, potency, dominance, say-so
• Official permission or approval.
  • usage: "authority for the program was renewed several times"
  • synonyms: authority, authorization, sanction
• The act of conferring legality or sanction or formal warrant.
  • synonyms: authorization, empowerment