(a.) Not doubted; not called in question; indubitable; indisputable; as, undoubted proof; undoubted hero.

accepted actual ascertained attested authenticated believed beyond question bona fide categorically true certain certified confirmed corroborated credited demonstrated determined documentary doubtless effectual established factual genuine historical indubious indubitable not in error objectively true past dispute proved questionless real received substantiated sure-enough TRUE true as gospel trusted truthful unchallenged unconfuted uncontested uncontradicted uncontroversial uncontroverted undenied undisputed unerroneous unfallacious unfalse unmistaken unquestionable unquestioned unrefuted unsuspected validated veracious verified veritable very