Bread and butter 这个组合除了有面包黄油的意思外，我们可以用它来指某人的谋生之道，生计或主要收入来源。

例句

You can't ask your neighbour to fix your car for free. He's a mechanic and fixing cars is his bread and butter.

Mary was very helpful to her clients. She knew they were her bread and butter.

请注意

另一个含有 butter 的短语是 to butter up, 意思是拍人马屁。

例句

Fred was new to the company but he didn't waste time before buttering up the boss.