to stop being involved in a situation, usually in order to allow other people to deal with it themselves

She started to criticize me, then she suddenly backed off. 她开始批评我，后来突然停了下来。

Just back off and let us do this on our own, will you? 你别管了，让我们自己来处理这事好吗？

to move backwards away from someone, usually because you are frightened

I saw the knife and backed off. 我看见那把刀，吓得连忙后退。