trass Meaning, Definition & Usage

D. tras or Gr. trass, probably fr. It. terrazzo terrace. See Terrace.

(Geol.) A white to gray volcanic tufa, formed of decomposed trachytic cinders; -- sometimes used as a cement. Hence, a coarse sort of plaster or mortar, durable in water, and used to line cisterns and other reservoirs of water. Formerly written also tarras, tarrace, terras. ✍ The Dutch trass is made by burning and grinding a soft grayish rock found on the lower Rhine.