The Collaborative International Dictionary of English v.0.48:

Unquestioned \Un*ques"tioned\, a.
   1. Not called in question; not doubted.
      [1913 Webster]

   2. Not interrogated; having no questions asked; not examined
      or examined into. --Shak.
      [1913 Webster]

            She muttering prayers, as holy rites she meant,
            Through the divided crowd unquestioned went.
                                                  --Dryden.
      [1913 Webster]

   3. Indisputable; not to be opposed or impugned.
      [1913 Webster]

            Their unquestioned pleasures must be served. --B.
                                                  Jonson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unquestioned
    adj 1: generally agreed upon; not subject to dispute; "the
           undisputed fact" [syn: undisputed, unchallenged,
           unquestioned]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "unquestioned":
   accepted, believed, beyond question, credited, doubtless,
   indubious, past dispute, questionless, received, trusted,
   unchallenged, uncontested, uncontradicted, uncontroversial,
   uncontroverted, undisputed, undoubted, unsuspected