Webster's English Dictionary

Enter the word to look up:

authoritative

au.thor.i.ta.tive \*-'tha:r-*-.ta-t-iv, o.-, -'tho.r-\ aj 1a: having or 
   proceeding from authority  1b: entitled to obedience, credit, or acceptance 
    2: DICTATORIAL, PEREMPTORY  - au.thor.i.ta.tive.ly av