im·par·tial (

m-pär

sh

l)
adj. Not partial or biased; unprejudiced.
impartial [ɪmˈpɑːʃəl]
adj not prejudiced towards or against any particular side or party; fair; unbiased
Adj.1.impartial - showing lack of favoritism; "the cold neutrality of an impartial judge"
fair,
just - free from favoritism or self-interest or bias or deception; conforming with established standards or rules; "a fair referee"; "fair deal"; "on a fair footing"; "a fair fight"; "by fair means or foul"
2.impartial - free from undue bias or preconceived opinions; "an unprejudiced appraisal of the pros and cons"; "the impartial eye of a scientist"