“附加”的意思是在原来的东西上再加上别的东西。

The meaning of "附加" is to add something extra to the original thing.

我们常说“附加条件”或“附加费用”，就是本来没有、后来加上去的部分。

We often say "附加条件" or "附加费用", which means parts that were not originally there but added later.