We can define "man" as someone's mental state.

Or we can define "man" as having XY chromosomes.

Before any debate can occur both parties need to agree on terminology and definitions.

Alternatively the argument could be about the legitimacy of the definitions themselves. Was liberty taken to redefine a word without standing?

It's not a matter of opinion, it's a matter of definition. I know what basic words mean. People can only disagree with the statements I made by destroying the meanings of the words I used. It's no big surprise that they're trying to do that, considering the source of this stuff is postmodernism.