Trass
[træs]
解釋/意思:
(n.) 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.
整理:肯尼思
解釋/意思:
n. a volcanic earth used as a hydraulic cement.
欧文整理