(1):

(a.) Not mal/ing a difference; having no influence or preponderating weight; involving no preference, concern, or attention; of no account; without significance or importance.

(2):

(a.) Neither particularly good, not very bad; of a middle state or quality; passable; mediocre.

(3):

(a.) Not inclined to one side, party, or choice more than to another; neutral; impartial.

(4):

(a.) Feeling no interest, anxiety, or care, respecting anything; unconcerned; inattentive; apathetic; heedless; as, to be indifferent to the welfare of one's family.

(5):

(a.) Free from bias or prejudice; impartial; unbiased; disinterested.

(6):

(adv.) To a moderate degree; passably; tolerably.