nonchalant (adj.)
- aloof
- apathetic
- ataractic
- benumbed
- blase
- calm
- careless
- casual
- cheerful
- collected
- comatose
- composed
- cool
- degage
- detached
- devil-may-care
- disinterested
- dispassionate
- distant
- dull
- easy
- easygoing
- effortless
- glad
- happy-go-lucky
- heartless
- heedless
- hopeless
- imperturbable
- inattentive
- incurious
- indifferent
- insouciant
- lackadaisical
- languid
- lethargic
- light
- lighthearted
- listless
- mindless
- negligent
- numb
- numbed
- offhand
- passive
- perfunctory
- phlegmatic
- reckless
- regardless
- relaxed
- slack
- sluggish
- smooth
- soporific
- spiritless
- stoic
- stupefied
- supine
- together
- torpid
- uncaring
- unconcerned
- undiscriminating
- undisturbed
- unemotional
- unenthusiastic
- unexcitable
- unexcited
- unflappable
- uninterested
- unmindful
- unperturbed
- unruffled
- untroubled
- withdrawn
