concern vs unconcern

concern and unconcern both are nouns.

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

concern (noun)	unconcern (noun)
something that interests you because it is important or affects you	the trait of remaining calm and seeming not to care; a casual lack of concern
something or someone that causes anxiety; a source of unhappiness	a feeling of lack of concern
a feeling of sympathy for someone or something
an anxious feeling
a commercial or industrial enterprise and the people who constitute it

concern (verb)	unconcern (verb)
be relevant to
be on the mind of