used for saying what is the best opinion you can have of somebody/something, or the best thing that can happen, when the situation is bad(表达最正面的看法或恶劣状况下可能出现的最好转机)充其量
Their response to the proposal was, at best, cool.他们对提议的反应充其量只能说是漠然置之。
We can't arrive before Friday at best.我们无论如何星期五之前也到不了。