[logfromblammo]

I have also heard it as "gypsum wallboard", which is certainly most descriptive.

I'm not certain whether the water-resistant, mold-resistant variety typically hung behind tiles in bathrooms is ever referred to as "wetwall" or if they still call it "drywall".

Nor am I aware of whether anyone calls the foil-backed, glass-reinforced, fire-resistant variety "firewall" instead of "drywall".

I wouldn't be surprised if obsolete and inapplicable names still attach to items with the same function. If we ever move to polyethylene film panels sandwiched with phase-change material for our walls, it might still be called "plasterboard" somewhere.

[marme]

it is called dry wall because it is installed while already dry. Unlike the old technique of lath and plaster where you build up the wall with multiple layers of wet plaster https://en.wikipedia.org/wiki/Lath_and_plaster