something that is added to something else in order to improve it or complete it; something extra

The doctor said she should be taking vitamin supplements. 医生说她应该服用维生素补充剂。

The money I get from teaching eveningnight classes provides a supplement to my main income. 我晚上教课所挣的钱可以补充我的主要收入。

We paid a supplement (= an extra amount of money) so that we could have a cabin on board the ship. 我们多付了一些钱，这样我们在船上就可以有一个单独的小舱住了。

a part of a magazine or newspaper, either produced separately or as part of the magazine or newspaper

The newspaper publishes a sports supplement every Monday. 这家报纸每周一出版一份体育副刊。

an extra part of a book, either produced separately or included at the end of the book, containing information that was not available when the book was first published

There is a supplement to the dictionary containing new words. 这部词典有一个新词附录。

to add something to something to make it larger or better

He supplements (= adds to) his income by working in a bar at night. 他晚上在酒吧打工以增加收入。

Some vegetarians like to supplement their diets with iron. 有些素食主义者喜欢在饮食之外吃一些含铁的药片。