1. Characterized by a lack of partiality
   "an unbiased account of her family problems";
   - indifferent, unbiassed [rare]
    
2. Without bias
   "The journalist strived to provide unbiased coverage of the controversial event";
   - unbiassed [rare]

1. Remove a bias (from)
   "The researchers worked to unbias their survey questions";
   - debias

See also: impartial, nonpartisan, nonpartizan [rare]

Encyclopedia: Unbiased