Why is the ninth month called September?
late 14c., "unbiased," from Old French indifferent "impartial" or directly from Latin indifferentem (nominative indifferens) "not differing, not particular, of not consequence, neither good nor evil," from in- "not, opposite of" (see in- (1)) + differens, present participle of differre "set apart" (see differ). Extended sense of "apathetic" first recorded early 15c.; that of "neither good nor bad" 1530s, on notion of "neither more nor less advantageous."
indifferent in·dif·fer·ent (ĭn-dĭf'ər-ənt, -dĭf'rənt)
Characterized by a lack of partiality; unbiased.
Not active or involved; neutral.
Undifferentiated, as cells or tissue.