“入乡随俗”，汉语成语，是指到一个地方，就顺从当地的习俗（conform to local customs/practices），与英语习语“when in Rome, do as the Romans do”意思相同。

例句：

我去伦敦总要带一把雨伞，入乡随俗嘛。

I always carry an umbrella when I visit London. When in Rome do as the Romans do.

俗话说，入乡随俗。所以我们吃中国料理的时候最好还是用筷子。

As the old saying goes, do as the Romans do, so we'd better eat the Chinese food by chopstick.