Where does “insouciance” come from?

Insouciance comes from French insouciance, formed from the French prefix in- and Latin in-, both meaning "not," ultimately deriving from Proto-Indo-European ne, meaning "not."

insouciance (English): carelessness, heedlessness, indifference, or...

Definitions

carelessness, heedlessness, indifference, or...

Ancestry of “insouciance”, step by step

Step	Language	Word	Meaning
1	French	insouciance	insouciance, unconcern
2	French	insouciant	carefree, without worries
3	French	souciant	worrying
4	French	soucier	to worry
5	Middle French	soucyer	to worry
6	Latin	sollicitō	—
7	Latin	sollicitus	Thoroughly moved, agitated or disturbed;...
8	Latin	sollus	whole, entire, unbroken
9	Proto-Italic	solnos	—
10	Proto-Indo-European	sol(h₂)nós	—
11	Proto-Indo-European	solh₂-	whole

Every word from Proto-Indo-European solh₂- →

insouciance — Etymology, Origin & Word History | Etymology Explorer