unquestionable -- (incapable of being questioned; "unquestionable authority")
authentic, bona fide, unquestionable, veritable -- (not counterfeit or copied; "an authentic signature"; "a bona fide manuscript"; "an unquestionable antique"; "photographs taken in a veritable bull ring")
unquestionable -- (not open to question; "an unquestionable (or unequivocal) loss of prestige")
(Sound)
