A noncrystalline, inorganic mixture of various metallic oxides fused by heating with glassifiers such as silica. Silica (SiO2) is a common component of glass.
O.E. glæs, from W.Gmc. *glasam (cf. M.Du. glas, Ger. Glas), from P.Gmc. base *gla-/*gle-, from PIE *gel-/*ghel- "to shine, glitter, be green or yellow," a color word that is the root of words for grey, blue, green, and yellow (cf. O.E. glær "amber," L. glaesum "amber," O.Ir. glass "green, blue, gray," Welsh glas "blue").