nonchalant

Adjective

WordNet 3.0

Adjective (1)

marked by blithe unconcern“an ability to interest casual students”“showed a casual disregard for cold weather”“an utterly insouciant financial policy”“an elegantly insouciant manner”“drove his car with nonchalant abandon”“was polite in a teasing nonchalant manner”Synonyms: casual insouciant

Webster's Dictionary (GCIDE)

Nonchalant \Non`cha`lant"\, a. [F., fr. non not (L. non) + chaloir to concern one's self for, fr. L. calere to be warm, to be inflamed with desire, to be troubled. See Non-, and Caldron.] Indifferent; careless; cool. [1913 Webster]