Bible Dictionaries
Trass

Webster's Dictionary

(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.

Bibliography Information
Webster, Noah. Entry for 'Trass'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​t/trass.html. 1828.