* "Ne" is the French word for "not," a common negative prefix.
* "Chaler" is an archaic French verb meaning "to care," "to be bothered," or "to be concerned."
Therefore, "nonchalant" literally means "not caring." This reflects the sense of indifference, coolness, and casualness that the word conveys.
The word entered English in the 17th century, initially used primarily in literary contexts. It eventually became part of common vocabulary, reflecting the enduring appeal of a relaxed and unconcerned attitude.