If you interrogate trans discourse a bit, you quickly find that a surprising number of people who should know better have a bad understanding of what "cis" means.
See, if you read between the lines, a lot of people parse "cis woman" as "woman who is biologically female".
What's the issue with this? Well, think about it. "Biologically female" is a fuzzy concept, you know this because of the memes where they epicly own the terfs by pointing out that attempting to nail down a clear definition leads to failure points such as excluding post-menopausal women, or infertile women, or any variety of obvious women depending on the "clever" new definition of "biological female" being deployed.
This is a problem that we've already resolved. Recall the acronym "AFAB", which colloquially means "biologically female" because precise terminology is doomed forever. It stands for "assigned female at birth", which if you scrutinize the word choice a bit, has some interesting choices:
"Assigned": This word implies that the process described is not, in fact, a naturalistic or automatic process. Assignments are typically performed by someone who holds power in a hierarchial structure, on a subject of lower standing in the hierachy.
"At birth": This word choice describes that the assignment is a one-time event, rather than an empirical quality of the individual.
From this, we can infer that the "female" being assigned here is in fact a socially constructed categorization, and implicitly, the same thing applies to the "AMAB" acronym.
What does this mean, in practice? It means that a baby will be provided with one of these assignments at birth. The assignment will be recorded and enforced systemically, and perceived deviations from the assignment have, in general, been pathologized because the assignment is prescriptive rather than descriptive.
Now, what is a cis person?
A cis person, at the most basic level, is someone who complies with the assignment.
Cisnormativity is the social mechanism coercing you to comply with the assignment, demanding justification for any act that deviates from that assignment, whether that's refusing "corrective" procedures for an intersex person, or transitioning.
It's not really about biology. It's about what society expects from you.
