(1):

(n.) The quality or state of being indifferent, or not making a difference; want of sufficient importance to constitute a difference; absence of weight; insignificance.

(2):

(n.) Passableness; mediocrity.

(3):

(n.) Impartiality; freedom from prejudice, prepossession, or bias.

(4):

(n.) Absence of anxiety or interest in respect to what is presented to the mind; unconcernedness; as, entire indifference to all that occurs.