:the smallest or easiest thing that someone can or should do某人能够（或应该）做的最起码的事
The least he could do is tell me what happened.他最起码应该告诉我发生了什么事情。
There's no need to thank me for my help. Considering all the help you've given me in the past, it was the least I could do. [=I do not deserve to be thanked for the small thing I did]不必言谢。想想过去你对我的所有帮助，这是我能做的最起码的事情。