the act of attacking someone with a broken bottle or glass

He was convicted of a vicious assault – a glassing where another man lost his right eye. 他被判恶性攻击——因为用玻璃瓶袭击一名男子并使其失去右眼。

They are looking at introducing plastic cups to deal with the growing number of glassings in pubs caused by intoxicated people. 他们正在考虑引进塑料杯，以应对酒吧里越来越多的醉酒者用玻璃杯伤人的事件。

the act of searching using binoculars (= a pair of tubes with glass lenses at either end that let you see things far away more clearly), for example when looking at animals in the wild

Binoculars are lightweight, portable, and great for glassing on the go. 双筒望远镜重量轻，便于携带，方便随时用来观察。

Just to see the bear was an amazing feat of glassing. 观察熊这个做法本身就是使用望远镜的一个壮举。