To identify the word most synonymous with "impartial," we must first define "impartial." "Impartial" signifies fairness and a lack of bias in any situation, adopting an objective viewpoint without favoritism. Let's examine the provided options:
- Biased: Indicates an unfair inclination for or against something, directly contradicting "impartial."
- Neutral: Denotes not favoring any side, being unbiased and fair, which is highly congruent with "impartial."
- Hostile: Implies unfriendliness or antagonism, unrelated to impartiality.
- Arrogant: Describes excessive pride, which does not align with impartiality.
Considering these definitions, "Neutral" is the word that most closely approximates the meaning of "impartial."