authoritative
1 accurate, authentic, definitive, dependable, factual, faithful, learned, reliable, scholarly, sound, true, trustworthy, truthful, valid, veritable
2 assertive, autocratic, commanding, confident, decisive, dictatorial, dogmatic, dominating, imperative, imperious, imposing, lordly, masterly, peremptory, self-assured
3 approved, authorized, commanding, legitimate, official, sanctioned, sovereign
1 deceptive, undependable, unreliable
2 humble, subservient, timid, weak
3 unauthorized, unofficial, unsanctioned