1. To place glass over something. In this usage, a noun or pronoun can be used between "glass" and "over." How expensive could it be to glass over this part of the wall?
2. To begin to look lifeless or dull. Typically used to describe someone's eyes. Your eyes are glassed over—did you work another 18-hour shift today?
glass over
v.
1. To cover something with glass or fiberglass: We glassed the surface over to keep water from seeping in.
2. To come to appear expressionless or lifeless. Used of the eyes: You should get some sleep—your eyes have glassed over.