Synonyms of authoritative

1 Syllable

truest, sound, royal, goer, truer, goest

2 Syllables

potent, big-gun, big-wheel, hot-dog, proven, valid, reigning, truthful, washer, delphian, legit, factual, old-line, standard, learned, faithful, trustier, namest, righteous, hotdog, namer

3 Syllables

trustable, judicial, authentic, influential, official, powerful, tyrannic, reliable, governing, supported, confirmed, orthodox, scholarly, trustworthy, attested, verified, imperious, juristic, sure-enough, doctrinal, unfaked, dominant, inerrant

4 Syllables

presidential, high-powered, managerial, responsible, oracular, infallible, legalistic, dependable, unchallenged, juridical, inarguable, inerrable, prescriptive, apodictic, canonical, overweighing, doctrinaire, veritable, undisputed, documented, predominant, unrefuted, accurate, buttoned-down, validated, uncontested

5 Syllables

undisputable, gubernatorial, supervisory, definitive, decision-making, incontestable, undeceivable, dominative, policy-making, overbalancing, authenticated, circumstantiated, authoritarian, policymaking, jurisdictional, unassailable, well-established, establishable

6 Syllables

administrative, organizational