Biscuit,
in general language, thin flour cake which has been baked in the oven until it is highly dried.
In pottery, articles molded and baked in an oven, preparatory to the glazing and burning. In the biscuit form, pottery is bibulous, but the glaze sinks into the pores and fuses in the kiln, forming a vitreous coating to the ware.
Entry from Everybody's Cyclopedia, 1912.