The Oxford Thesaurus An A-Z Dictionary of Synonyms - indifferencen.

1) unconcern, apathy, listlessness, disinterest, coolness, nonchalance, insouciance, aloofness, detachment, disregard, inattention, pococuranteism or pococurantism, coldness, phlegm, stolidity, callousness, insensibility, impassiveness or impassivity: I cannot believe the indifference she showed on learning about the tragedy. 2) unimportance, insignificance, irrelevance, unconcern, inconsequence, triviality: Whether I go or stay is a matter of indifference to me. 3) dispassion, disinterestedness, impartiality, neutrality, objectivity, fairness, equitableness, even-handedness: The judges demonstrated their indifference by awarding first prize to a novice.