- (geology) A white to grey volcanic tufa, formed of decomposed trachytic cinders, sometimes used as a cement.
- A coarse sort of plaster or mortar, durable in water, and used to line cisterns and other reservoirs of water.
Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.
(See the entry for trass in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.)
- tross (Bokmål)
- “trass” in The Nynorsk Dictionary.