insouciant [in-soo-see-uh nt; French an-soo-syahn]
1. free from concern, worry, or anxiety; carefree; nonchalant.
lighthearted, debonair, jaunty, breezy.
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Origin: 1820-30; < French, equivalent to in- in-3+ souciant present participle of soucier to worry < Vulgar Latin *sollicītāre, for Latin sollicitāre to disturb; see solicitous
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