- a light-colored type of volcanic tuff used in making water-resistant cement and mortar.
Examples from the Web for trass
Historical Examples of trass
He wished that the Trass boy would talk forever about destiny.
But the Trass boy finished his remarks about destiny in a very short time.
The Dutch are very attentive in ascertaining the quality of the trass before using it in building their dikes.An Account of the Bell Rock Light-House
Sometimes a proportion of common sand mortar instead of lime is mixed with the trass.
Trass, tras, n. a volcanic earth used as a hydraulic cement.
- a variety of the volcanic rock tuff, used to make a hydraulic cement