It is more basic than gender. "Cis" is the antonym of "Trans." So anything that has a "trans" also has a "cis." For example, in ancient Rome, there were two Gauls: Transapline Gaul and Cisalpine Gaul. The former was "Gaul on the other side of the Alps" and the latter was "Gaul on this side of the Alps." That's all it is. A directional term. It's perfectly appropriate to refer to womyn-born-womyn (as the feminists call themselves) as "cis" women in contradiction to "trans" women.Basic Latin has no jurisdiction in gender.
This isn’t ’nam. There are rules.