As detailed above, 'indifferent' can be an adverb or an adjective. Adverb usage: The face of the Moon appearing to me to be full of indifferent high mountains... Adjective usage: He was indifferent to the proposal, since it didn't affect him, either way.

Is indifferent an adjective or adverb?

indifferent adjective (NOT INTERESTED)

Is indifference an adjective?

Not caring or concerned; uninterested, apathetic. Mediocre, usually used negatively in modern usage. Having no preference or bias, being impartial.