cup 指有柄，用来饮茶或咖啡等的瓷杯。
glass 指玻璃制的杯子，用来盛酒和牛奶等东西。
mug 通常指周边垂直，不用茶托的有柄大瓷杯或大金属杯。
参考例句
1. He was mugged from behind and forced into a dark room. 他从背后被勒住脖子，被迫进入一间黑屋。
2. What a beautiful mug! 多漂亮的杯子啊！
3. What is the difference between coffee mug and others? 咖啡杯与其它杯子的区别是什么？
英英解释
n.
1. the quantity that can be held in a mug
2. a person who is gullible and easy to take advantage of
3. the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)
4. with handle and usually cylindrical v.
1. rob at gunpoint or with the threat of violence
