Glass — a transparent or translucent material used for windows, containers, etc. Often written in katakana, with the kanji 硝子 used occasionally.
窓ガラスが割れているので交換しないといけない。
The window glass is broken, so it needs to be replaced.
ガラスのコップにジュースを注いだ。
I poured juice into a glass cup.
昔の硝子は今より厚く、色がついていることが多い。
Old glass was often thicker and sometimes colored compared to today.