authoritative

1 being the most accurate and apparently thorough this book is considered the most authoritative source on that subject Synonyms definitive, classic, classical, magisterialRelated Words conclusive, decisive; approved, official, sanctioned; accurate, correct; complete, comprehensive, exhaustive, thorough

2 having power over the minds or behavior of others after a couple of authoritative critics panned the movie, the other reviewers rushed to say how awful it was Synonyms influential, forceful, weightyRelated Words cogent, controlling, dominating, masterful; dominant, predominant, regnant, sovereign (also sovran), supreme; eminent, important, momentousNear Antonyms helpless, impotent, powerless, weak; incapable, unable

3 fond of ordering people around she's very authoritative for someone who doesn't actually outrank us Synonyms authoritarian, bossy, autocratic (also autocratical), despotic, dictatorial, domineering, imperious, masterful, overbearing, peremptory, tyrannical (also tyrannic), tyrannousRelated Words arrogant, assumptive, disdainful, fastuous, haughty, highfalutin (also hifalutin), high-and-mighty, high-hat, huffy, important, lofty, lordly, overweening, presuming, presumptuous, pretentious, proud, self-asserting, supercilious, superior, toplofty (also toploftical), uppish, uppity; commanding, controlling, dictating, regimental; arbitrary, high-handed, imperial; directorial, magisterial; aggressive, assertive, self-assertive; imperative; conceited, narcissistic, pompous, vain; all-powerful, almighty, omnipotent; firm, sternNear Antonyms humble, meek, modest, unassuming; amenable, docile, obedient, tractable; indecisive, irresolute; acquiescent, compliant, passive, resigned, submissive, yielding