C19: from French, from in-1 + souciant worrying, from soucier to trouble, from Latin sollicitāre; compare solicitous
insouciant for learners of EnglishPowered by COBUILD (ɪnsuːsiənt)
graded adjective & adjective
An insouciant action or quality shows someone's lack of concern about something which they might be expected to take more seriously. [formal] [+ about] ⇒ Programme-makers seem irresponsibly insouciant about churning out violence.
she asked with an edge to her voice that made even the insouciant Ailie cringeslightly.Brent-Dyer, Elinor ADRIENNE AND THE CHALET SCHOOLReally, in politics these days one has got to be a bit more - insouciant.Barnard, Robert POLITICAL SUICIDE'No,' said Julia, thinking all the way back to the insouciant little girlpoking her hard in the leg with a pencil in Year One.Jenny Colgan LOOKING FOR ANDREW MCCARTHYOur insouciant young man who pretends to be so dense and full of disregard for world affairs isn't at all what he appears to be.James W. Hall OFF THE CHART