unconcern vs carefreeness

unconcern and carefreeness both are nouns.

Word	Noun	Adjective	Verb	Adverb
unconcern	Yes	No	No	No
carefreeness	Yes	No	No	No

As nouns, carefreeness is a hypernym of unconcern; that is, carefreeness is a word with a broader meaning than unconcern:

unconcern: the trait of remaining calm and seeming not to care; a casual lack of concern
carefreeness: the trait of being without worry or responsibility

unconcern (noun)	carefreeness (noun)
the trait of remaining calm and seeming not to care; a casual lack of concern	the trait of being without worry or responsibility
a feeling of lack of concern	the cheerful feeling you have when nothing is troubling you