In the end I conclude that the fact that female humans are full people with different opinions, experiences, preferences, ambitions, modes of dress, experiences etc is essentially transphobic
When a more precise definition of the word woman is requested than 'anyone who says they are one', there are many different answers.
Ones I've seen (not going to look them all up but Google will help if anyone wants the original quotes).
Women are formless
The ones who take the passive role in sex
Blank eyes and an expectant arsehole
I'm sure there are plenty more but there's a few to start with.
The point is that the word can have no explicit definition as different individuals want to define it however they see fit.
Therefore of course the fact that women in real life reject definitions like these (say no) and insist that we need words to describe the female half of the human race. And woman = adult human female is therefore a word already taken and not to be reimagined as whatever it means to the speaker. Is of course transphobic.
And I suppose this is where the idea of denying existence comes from too.