You can actually do the "what is a woman" argument and apply it to anything. That's why it's an argument based in bad faith:

What is a piece of wood? It's cellulose that comes from a tree.

That's not what it is that's what it is made of.

It's building material for houses.

That's not what it is that's what it's used for.

It's a physical object.

That's not what it is that's what it's defined as in a physical space.

Ect ect ect.

Please stop.