the.com/plasterboard

means A flat building panel made of a gypsum core pressed between two sheets of heavy paper, used to form interior walls and ceilings.

from Straightforward compound: 'plaster,' from Greek 'emplastron' (something molded or daubed on), via Latin and Old French into English — and 'board,' an old Germanic word for a flat slab of wood or material used in building. Put together in the 19th/20th century as the wet-plaster trade got replaced by prefabricated gypsum panels; the name simply describes the thing — plaster, but in board form, ready to nail up instead of trowel on.