What does "unconcerned" mean?

Unconcerned: Not concerned; not anxious or solicitous; easy in mind; carelessly secure; indifferent; as, to be unconcerned at what has happened; to be unconcerned about the future. -- Un`con*cern"ed*ly, adv. -- Un`con*cern"ed*ness, n. Happy mortals, unconcerned for more. Dryden.