First as required by the obvious ethics I will note that I am male and that what I'm writing here is informed by radical feminists and other feminists, and women in general. I can only thank them for forming my understanding of my personal experience and reality. This post is more of a thought experiment than it is a statement of my personal beliefs; that said, the lens I lay out below has allowed me to understand the world more clearly than any other way of thinking.
A lot is discussed regarding gendered slurs: the b-word, the c-word, the s-word. But I think that "woman" is already a slur. As is "girl". You can see this with clarity by observing what happens when a young boy is called a "girl".
What is a "slur"? A slur is a violent word used by the socially powerful to refer to the socially powerless. The word "woman" is the combination of the Old English words for "wife" and "man", or in other words "property person". So the word "woman" was born of violence: the violence inherent in female-as-property, female-as-vessel. The word was created by men (who else?) and is still used by men as a slur. Most female people call themselves "woman", as in reclaim it, put it in a different context, as has been done with slurs in history. But for men the original connotation survives today: "woman" still refers to property (public and/or private), to vessels of reproduction.
As soon as the doctor claims "it's a girl", the parent(s) react to the charge. "Toys" are purchased that train this child for their future state of subordination. The child is marked with colors and fashion that delineate their status. They are discouraged from engaging in activities reserved for ordinary human beings, for they are a "woman". This is violence that a parent can invite on a baby of theirs, even if the child is male, by using the word "girl" for them, since the biological markers aren't yet present; no one checks the genitals of a "girl" before inching the rug out from under "her" year by year ("...much like drips of water onto a rock; you don't notice the erosion it causes, because it's subtle, and it's daily, and it's by inches...") -- it is all based entirely on an imagined inferiority.
What is the exact meaning of the slur "woman"? I feel that if we imagine a society in which humans have invented service robots that look similar to humans, but are not as capable and obviously not conscious, we can maybe imagine "woman" as a slur akin to a casual denigrating nickname for these robots. "Woman" refers to a multipurpose android (literally "man-shaped"): it dispenses PIV (penis-in-vagina sex) and performs the visual arousal associated with it, and handles child incubation and care, attention-giving, and a few other things.
"Women"-robots used to be considered strictly privately owned, but with time they have achieved the status of public property (if such is their programming). "Women", when they are "girls", are not usually educated in the sciences and arts that concern human beings, but instead are trained ("groomed" is a word used by some radical feminists) for their small set of future tasks, to be completed over and over until death.
"Women"-robots (who, after all, are actually people) have had to make progress in lifting off corners of this blanket of cultural slander and oppression completely on their own, and it has taken thousands of years to expand the definition of the slur slightly to perhaps mitigate some types of violence it inspires, but the slur remains, albeit buried under popular culture and various kinds of appropriations. But burying something does not change its usefulness, its gravity, its potential to mold the target for use by men.
A "woman"-robot function of particular importance is PIV-dispensing. A subset of men, for some reason, like to do things with each other that are akin to PIV-dispensing (the prostate gland is a pleasure center for many/all males after all), which confuses other men who see this as wrong -- a human being shouldn't be doing that kind of thing. Some men find the idea of robots and being a robot fun, for some reason. They become cyborgs (attempting to gain the functionality of "women" through medical technology) and assert that they are now "women". Other men find this confusing and wrong too. These men are treated like "women"-robots, mentally ill people, or otherwise inferior beings.
Some "women"-robots are "born without" PIV-dispensing programming (i.e. they don't want to do it) or decide to stop dispensing PIV. It seems they are subjected to what one would expect, though I can't speak for them.
In interpreting "woman" as a slur that implies a certain "functionality" for the benefit of the (hu)man, the oppression and violence women face is indeed "biological" in that sense. The bodies of women, and the physical movements of those bodies, are resources, whether viewed individually or collectively. A "woman"-robot's failure to live up to what it has been told is its programming often results in a range of attempts at self-troubleshooting, which can reach self-destruction, for example "eating disorders".
"Women" must remain resources; they must be convinced that the extent of their resourcehood is literally their worth (wouldn't you want your robot to want to perform its functions?) Collective action by "woman"-robots is concerning to men (wouldn't you be concerned if your robots started organizing?), but luckily it was and is not too hard to apply pressure to keep the ideologies that equate functionality with liberty in the mainstream, and to marginalize the movements that threaten to trace and describe reality, like radical feminism. By natural selection, the most libertarian feminism will be the most widespread; it criticizes the activities involved in resourcehood the least, with "non-consensual" PIV-dispensing as a notable exception, in that it very difficult to present this activity to women as something that could be free from criticism, what with "Woman"(-Robot) Rights already enacted in the "Western world" (but men frequently succeed at convincing women anyway, for example in the BDSM community).
The word "woman", then, is an umbrella term for the functionality of the "woman"-robot I'm describing here. The word "woman" is used by men to refer to female people by the degrading, literally dehumanizing acts involved in carrying out womanly functionality as a service to men. Young boys are highly perceptive and pick up that "woman" is a bad thing to be, but they can't possibly figure out why (it took me a couple of decades); they just know it's bad and don't want to be called one. (Young "girls", highly perceptive as well, pick up that gendered insults like "manly" are bad because, well, that's not being functional.)
It's always been this way and still is. Men do all this and they know they do it. Men would probably not know what to do if "women" rejected slurs and refused resourcehood. The rage that men direct at radical feminists can be taken as an example of what might happen in a situation like that. I'm not saying that dropping the word "woman" is The Answer (once again I know that "woman" is used by a lot of people a lot of different ways), or that mass refusal of sex with men and childbearing is The Answer, I'm just observing that I just don't know what men would do if that became a thing.
"The ideologies of colonial cultures – race, class, gender – all serve the purpose of normalizing and rendering invisible the mechanics of resource extraction." -Rachel Ivey