I think it's easy to assume that "woman" means "vagina" but from a feminist perspective isn't that a bit reductionist and dehumanising? To think we're only defined by our genitals?
Yes, that would be dehumanising. But it's your side calling women "vagina-owners" or "uterus havers", not ours
"Woman" means "adult human female". "Man" means "adult human male".
We're not defining women. We're defining "women" - ie defining the word "woman". Can you see the difference?
(For "defining women" in the first phrase to even mean something you have to know what you mean by "defining" and "women"...)
Anyone saying we're "defining women" is being dishonest. You could say the same thing about any classification.
"I think it's easy to assume that "Welsh" means "from Wales", but from a Welsh perspective isn't that a bit reductionist and dehumanising? To think we're only defined by our nationality?"
"I think it's easy to assume that "blind" means "can't see", but from a disability perspective isn't that a bit reductionist and dehumanising? To think we're only defined by our lack of sight?"
"I think it's easy to assume that "vegan" means "doesn't eat animal products", but from a nutritional perspective isn't that a bit reductionist and dehumanising? To think we're only defined by our food choices?"
"I think it's easy to assume that "homosexual" means "attracted to members of the same sex", but from a relationship perspective isn't that a bit reductionist and dehumanising? To think we're only defined by our sex lives?"
etc etc
No, we're just saying words mean things. And it's useful if they continue to do so, cos it lets you talk about stuff.