- nonchalant (adj.)
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- 1734, from French nonchalant, present participle of nonchaloir "be indifferent to, have no concern for" (13c.), from non- "not" (see non-) + chaloir "have concern for," ultimately from Latin calere "be hot" (see calorie). French chaland "customer, client" is of the same origin. Related: Nonchalantly.