adj. 25B6; adjective
an authentic document : GENUINE, real, bona fide, true, veritable, simon-pure; legitimate, lawful, legal, valid; informal the real McCoy, the real thing, pukka, kosher; Austral./NZ informal dinkum.
an authentic depiction of the situation : RELIABLE, dependable, trustworthy, authoritative, honest, faithful; accurate, factual, true, truthful; formal veridical, veracious.
fake, unreliable.