Complementary describes things that go well together because they complete or enhance each other. When two things are complementary, each one supplies what the other lacks, making both more effective as a pair.

In color theory, complementary colors sit opposite each other on the color wheel: red and green, blue and orange, yellow and purple. Artists use these pairs because they create vibrant, eye-catching contrasts that make each color appear more intense. A blue sky makes orange autumn leaves seem even brighter.

Skills can be complementary too. If you're great at creative writing but struggle with organization, and your friend excels at outlining and editing but finds it hard to generate ideas, your abilities are complementary. Working together, you create something better than either could alone.

The word comes from complete, and that's the key: complementary things fit together like puzzle pieces, each filling in what the other needs. Peanut butter and jelly are complementary flavors. A catcher's steady focus complements a pitcher's powerful arm.

Don't confuse this with complimentary (with an i), which means giving praise or providing something for free. When a hotel gives you a complimentary breakfast, they're giving you a freebie, not completing you.