trass

American  

[tras] / træs /

noun

1. a light-colored type of volcanic tuff used in making water-resistant cement and mortar.

---

trass British  

/ træs /

noun

1. a variety of the volcanic rock tuff, used to make a hydraulic cement

---

Etymology

Origin of trass

First recorded in 1790–1800; from Dutch trass, from earlier terass, tieras, tiras “brick dust, rubbish,” from French terrasse; see terrace ( def. )

Example Sentences

The manner in which this trass conforms to the shape of the present valleys implies its comparatively modern origin, probably not dating farther back than the Pliocene Period.

From The Student's Elements of Geology by Lyell, Charles, Sir

You must not suppose the stream to be clear like the Aar, for it is as thick as pea-soup, and about the same colour, being in fact a river of trass in solution.

From The Mirror of Literature, Amusement, and Instruction Volume 12, No. 326, August 9, 1828 by Various

Generally speaking, they are only of local importance, their cheapness depending largely on the nearness and abundance of some suitable volcanic deposit of the trass or tufa class.

From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 6 "Celtes, Konrad" to "Ceramics" by Various

Mixing very finely-ground silica, or trass, with the cement proved an advantage where a weak mixture was employed, but in the other cases no benefit was observed.

From The Sewerage of Sea Coast Towns by Adams, Henry C.

He proposed to neutralise this action by adding to the mortar materials rich in silica, such as trass, which would combine with the lime.

From The Sewerage of Sea Coast Towns by Adams, Henry C.