It's only used anymore in the words "nonchalant" (someone to which things don't matter much) and the expression "peu me chaut" (it matters little to me).

But although "nonchalant" has a clear meaning, the meaning of "chalant" wouldn't be as obvious, since while it's easy to not care about things generally, "generally caring about things" is just the normal state of a person. It's the same reason you don't often hear about a stoppable force or a wieldy tool.