a. | 1. | Having, or proceeding from, due authority; entitled to obedience, credit, or acceptance; determinate; commanding. |
2. | Having an air of authority; positive; dictatorial; peremptory; |
Adj. | 1. | authoritative - having authority or ascendancy or influence; "an important official"; "the captain's authoritative manner" Synonyms: important |
2. | authoritative - of recognized authority or excellence; "the definitive work on Greece"; "classical methods of navigation" Synonyms: classical, definitive | |
3. | authoritative - sanctioned by established authority; "an authoritative communique"; "the authorized biography" Synonyms: authorised, authorized |