trass
n. சீமைக்காரையாக இறக்குமதி செய்யப்பெற்ற எரிமலைக்குழம்புப் பொடி.
Trass, n. Etym: [D. tras or Gr. trass, probably fr. It. terrazzo terrace. See Terrace.] (Geol.) Defn: 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.] Note: The Dutch trass is made by burning and grinding a soft grayish rock found on the lower Rhine.