Synonyms of authoritative in English:

authoritative


See US English definition of authoritative

See UK English definition of authoritative

See Spanish definition of fidedigno

adjective

1‘authoritative information’

SYNONYMS
reliable, dependable, trustworthy, good, sound, authentic, valid, well founded, attested, certified, verifiable
accurate, factual, from the horse's mouth
ANTONYMS

unreliable

2‘the authoritative edition’

SYNONYMS
definitive, most reliable, best, most scholarly
classic
authorized, accredited, recognized, accepted, approved, sanctioned

3‘his authoritative manner’

SYNONYMS
self-assured, assured, self-confident, confident, sure of oneself
commanding, imposing, masterful, magisterial, lordly, assertive, dogmatic, peremptory, arrogant, dominating, domineering, imperious, overbearing, bossy, authoritarian
ANTONYMS

timid, diffident