indifference vs passiveness

indifference and passiveness both are nouns.

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

As nouns, passiveness is a hypernym of indifference; that is, passiveness is a word with a broader meaning than indifference:

indifference: the trait of lacking enthusiasm for or interest in things generally
passiveness: the trait of remaining inactive; a lack of initiative

Other hypernyms of indifference include passivity.

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