authoritative (adj.)youdaoicibaDictYouDict[authoritative 词源字典]
c. 1600, "dictatorial" (a sense now restricted to authoritarian), from Medieval Latin authoritativus (see authority). Meaning "possessing authority" is recorded from 1650s; that of "proceeding from proper authority" is from 1809. Related: Authoritatively; authoritativeness.[authoritative etymology, authoritative origin, 英语词源]