Refers to glass with a roughened, non-transparent surface, used for windows, partitions, or decorative items.
The bathroom window is made of frosted glass.
I poured a cold drink into a frosted glass.
Kanji spelling using 磨る; less common than kana but still encountered.
Kanji spelling using 擦る; less common than kana but still encountered.
Compound of すり (連用形 of する, 'to grind, rub') and ガラス ('glass'). The kana spelling is standard.