mouth 嘴巴的意思，watering，流口水；字面来看是嘴巴流口水，in English， Having one's appetite enticed. 令人垂涎的

　　来源：

　　This expression is simple enough: 这个俚语很简单The 'water' is not actually water, but saliva that your body will produce when you eat something.这里提到的water实际不是水，而是当我们吃东西时候身体产生的唾液 Sometimes, a person can start this extra saliva production by just thinking about food. 有时候，人们在想到食物的时候就会开始产生唾液Thus, when food is on the mind, a person 'waters' at the mouth.因此，当想到食物时，一个人的嘴巴就会湿；

　　举例：

　　On the way home, I had the imagination of much mouth watering food on the table.

　　在回家的路上，我幻想着满桌的可口饭菜。

　　You can see his mouth watering, let's start to eat right now.

　　看他那垂涎欲滴的样子，快开始吃饭吧。