Definitions:
a hard, brittle substance, typically transparent or translucent, made by fusing sand with soda and lime and cooling rapidly. it is used to make windows, drinking containers, and other articles

a drinking container made from glass

a lens, or an optical instrument containing a lens or lenses, in particular a monocle or a magnifying lens.

a mirror

cover or enclose with glass

(especially in hunting) scan (one's surroundings) with binoculars

hit (someone) in the face with a beer glass

reflect as if in a mirror