authoritative

Adjective

• sanctioned by established authority
  • an authoritative communique
    
  • the authorized biography
    

• of recognized authority or excellence
  • the definitive work on Greece
    
  • classical methods of navigation
    

• having authority or ascendancy or influence
  • an important official
    
  • the captain's authoritative manner
    

Related words

• Synonyms: 
  authorized , authorised , classical , classic , definitive , important