well 表程度，意为“非常地；十分地；完全地”，主要用来修饰介词短语。例如：

This restaurant is well worth a visit. 

这家饭店非常值得光顾一番。

《柯林斯高阶英汉双解学习词典》

His work is well above the average. 

他的工作远高于一般水平。

well 还可以修饰部分过去分词或形容词：

This reminds us that we must keep people well informed of the facts about flu. 

这提醒我们必须让人们充分了解有关流感的事实。

He is well known for his painting.

他以绘画闻名。

They are well aware of this. 

他们都清楚地意识到了这点。

We've got well over 40000 people infected.

【翻译】我们已经足足有4万多人感染了。