indifference vs indifferent

indifference is a noun but indifferent is not a noun.

Word	Noun	Adjective	Verb	Adverb
indifference	Yes	No	No	No
indifferent	No	Yes	No	No

indifference (noun)	indifferent (noun)
the trait of lacking enthusiasm for or interest in things generally
the trait of remaining calm and seeming not to care; a casual lack of concern
unbiased impartial unconcern
apathy demonstrated by an absence of emotional reactions

indifference (adjective)	indifferent (adjective)
	(usually followed by `to') unwilling or refusing to pay heed
	characterized by a lack of partiality
	fairly poor to not very good
	neither too great nor too little
	being neither good nor bad
	showing no care or concern in attitude or action
	(often followed by `to') lacking importance; not mattering one way or the other
	marked by a lack of interest
	having only a limited ability to react chemically; chemically inactive
	marked by no especial liking or dislike or preference for one thing over another