n. [ F. matras; perh. so called from its long narrow neck; cf. OF. matras large arrow, L. materis, mataris, matara, a Celtic javelin, pike; of Celtic origin. ] (Chem.) A round-bottomed glass flask having a long neck; a bolthead. [ 1913 Webster ]
n. [ So called from its inventor, a German jeweler: cf. F. stras. ] (Chem.) A brilliant glass, used in the manufacture of artificial paste gems, which consists essentially of a complex borosilicate of lead and potassium. Cf. Glass. [ 1913 Webster ]
n. [ D. tras or Gr. trass, probably fr. It. terrazzo terrace. See Terrace. ] (Geol.) 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.
☞ The Dutch trass is made by burning and grinding a soft grayish rock found on the lower Rhine. [ 1913 Webster ]