The Collaborative International Dictionary of English v.0.48:

Unprejudiced \Un*prej"u*diced\, a.
   1. Not prejudiced; free from undue bias or prepossession; not
      preoccupied by opinion; impartial; as, an unprejudiced
      mind; an unprejudiced judge.
      [1913 Webster]

   2. Not warped or biased by prejudice; as, an unprejudiced
      judgment.
      [1913 Webster] -- Un*prej"u*diced*ness, n. --V. Knox.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unprejudiced
    adj 1: free from undue bias or preconceived opinions; "an
           unprejudiced appraisal of the pros and cons"; "the
           impartial eye of a scientist" [syn: unprejudiced,
           impartial] [ant: discriminatory, prejudiced]

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "unprejudiced":
   detached, disinterested, dispassionate, equitable, evenhanded,
   fair, fair-minded, impartial, impersonal, indifferent, just,
   liberal, neutral, objective, open-minded, unbiased, unbigoted,
   uncolored, undazzled, undogmatic, uninfluenced, unjaundiced,
   unprepossessed, unswayed