— nonchalantly , adv.
/non'sheuh lahnt", non"sheuh lahnt', -leuhnt/ , adj.
coolly unconcerned, indifferent, or unexcited; casual: His nonchalant manner infuriated me.
[ 1725-35; nonchalant, prp. of obs. nonchaloir to lack warmth (of heart), be indifferent, equiv. to non- NON- + chaloir calere to be warm. See -ANT ]
Syn . cool, calm, collected, composed.
Ant . excitable.