n.

1. the power or right to give orders or make decisions;
   authorization, authorisation, potency, dominance, say-so
   
   • he has the authority to issue warrants
   • deputies are given authorization to make arrests
   • a place of potency in the state
2. (usually plural) persons who exercise (administrative) control over others
   
   • the authorities have issued a curfew
3. an expert whose views are taken as definitive
   
   • he is an authority on corporate law
4. freedom from doubt; belief in yourself and your abilities;
   assurance, self-assurance, confidence, self-confidence, sureness
   
   • his assurance in his superiority did not make him popular
   • after that failure he lost his confidence
   • she spoke with authority
5. an administrative unit of government;
   agency, federal agency, government agency, bureau, office
   
   • the Central Intelligence Agency
   • the Census Bureau
   • Office of Management and Budget
   • Tennessee Valley Authority
6. official permission or approval;
   authorization, authorisation, sanction
   
   • authority for the program was renewed several times
7. an authoritative written work
   
   • this book is the final authority on the life of Milton