从字面上看，短语 “overstep the mark” 的意思是 “超越界线”，它的实际意思是 “做出格、过分的事情”。在这个短语中，动词 “overstep” 的意思是 “超出、逾越”，而名词 “mark” 表示 “某事被允许或可以接受的限度”。

例句

Connor really overstepped the mark when he shouted at Abi. You just can't do things like that!
康纳冲着艾比大喊大叫，真是太过分了。绝不应该有这样的行为！

I don't want to overstep the mark here, but I need to ask you about your family.
我不想问得太多，但我需要问问你的家庭情况。

I was friends with Siqi but she overstepped the mark when she didn't give that money back.
我和思琪本是朋友，但当时她不还钱，做得太过分了，越过了我的底线。