Something that completes or goes well with something.

पूरक

English Usage: The wine was a perfect complement to the cheese.

Hindi Usage: वाइन पनीर का एकदम सही पूरक था।

To add to something in a way that enhances or improves it.

पूरक बनाना

English Usage: The new curtains complement the room's decor beautifully.

Hindi Usage: नए परदे कमरे की सजावट को खूबसूरती से पूरक बनाते हैं।