well done意思是干得好。
一般情况下是一种"感叹"的语气，当别人某件事干得漂亮时所给予的夸奖。well done在吃牛排时，是形容牛排全熟。
例句
When I found my son raised his hand and started call out wildly, "Well done, Mickey!"
当我发现我儿子举起手开始疾呼：“干得好！米奇！”
Please give me a hamburger, well done.
请给我一份熟透的汉堡牛排。
He observed to me that our work was very well done.
他对我说我们的工作做得很好。
