(a.) 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.

Laodicean Olympian aloof apathetic ataractic benumbed blah blase bored careless casual collected comatose composed cool degage desensitized detached devil-may-care disinterested dispassionate disregardful distant dull easy easygoing free and easy heartless hebetudinous heedless hopeless impassive in a stupor inattentive incurious indifferent inexcitable insouciant lackadaisical languid lethargic listless mindless negligent nonchalant numb numbed offhand passive perfunctory phlegmatic pluckless pococurante reckless regardless remote resigned slack sluggish soporific spiritless spunkless stoic stolid stupefied supine torpid turned-off unanxious uncaring undiscriminating uninquiring uninterested uninvolved unmindful unsolicitous withdrawn