Lack of interest or care; indifference or apathy. / Freedom from worry or apprehensiveness; insouciance or nonchalance.

Indifferent and having no interest; aloof. / Not anxious, apprehensive, or worried. / Having no involvement.

plural of unconcern

(obsolete) Not interesting or affecting; insignificant.

(obsolete) Lack of concern; unconcern.

In an unconcerned manner.

The state or condition of being unconcerned.

Archaic form of unconcerned.