adjective (a)

• free from undue bias or preconceived opinions(adj.all)

  Example:
  An unprejudiced appraisal of the pros and cons.
  

  Synonym:
  impartial
  Antonym:
  discriminatory, prejudiced
  

  source: wordnet30
• Not prejudiced; free from undue bias or prepossession; not preoccupied by opinion; impartial; as, an unprejudiced mind; an unprejudiced judge.(adjective)

  source: webster1913