A hard, brittle substance, typically transparent or translucent, made by fusing sand with soda, lime, and sometimes other ingredients and cooling rapidly. It is used to make windows, drinking containers, and other articles. A thing made from, or partly from, glass, in particular. A lens, or an optical instrument containing a lens or lenses, in particular a monocle or a magnifying lens. The liquid or amount of liquid contained in a glass; a glassful. Cover or enclose with glass. (especially in hunting) scan (one's surroundings) with binoculars. Reflect in or as if in a mirror.