complementary

[ kom-pluh-men-tuh-ree, -tree ]

adjective

1. forming a complement; completing.
2. complementing each other.

noun

, plural com·ple·men·ta·ries.

1. complementary color ( def 1 ).

complementary

/ -trɪ; ˌkɒmplɪˈmɛntərɪ /

adjective

1. acting as or forming a complement; completing
2. forming a satisfactory or balanced whole
3. forming a mathematical complement

   sine and cosine are complementary functions

4. maths logic (of a pair of sets, etc) mutually exclusive and exhaustive, each being the complement of the other
5. (of genes) producing an effect in association with other genes
6. involving or using the treatments and techniques of complementary medicine

Derived Forms

• ˌcompleˈmentariness, noun
• ˌcompleˈmentarily, adverb

Other Words From

• comple·menta·ri·ness noun
• uncom·ple·menta·ry adjective

Word History and Origins

Origin of complementary¹

First recorded in 1590–1600; complement + -ary

Example Sentences

Previous studies of endosymbiosis have shown that there can be complementary gene losses between hosts and endosymbionts, creating a metabolic interdependence.

From Quanta Magazine

The algorithms behind social media giants are designed to funnel viewers through a vortex of complementary interests — basically, to keep feeding them content they like in order to maintain interest and engagement.

From Ozy

In an increasingly complex and interdependent world, much more can be accomplished by working with partners who have different, yet complementary, skills.

From Fortune

Grocery advertisers should adopt an “always-on” strategy by cross-promoting products on both similar and complementary keywords.

From Search Engine Land

To Eric von Hippel’s point about the complementary relationship between home innovators and firms, Dana Lewis and her co-inventors have licensed their algorithm to healthcare companies to use in their devices.

From Freakonomics

To an extent, such ambitions are complementary, yet Liana is not interested in “extreme biography.”

From The Daily Beast

He added that “the method is not a better method, but complementary to other methods.”

From The Daily Beast

If galaxy mapping is like doing a population map, the complementary study is like a demographic survey.

From The Daily Beast

According to Sig Gissler, who administered the awards, the two series of stories “were complementary.”

From The Daily Beast

Between them, the four of them being so complementary, they managed to appeal to almost everyone.

From The Daily Beast

He placed it in prominence, instinctively or designedly, rejecting the merely complementary parts.

From Project Gutenberg

This has occurred with regard to agricultural investments, which have awaited a complementary organic legislation.

From Project Gutenberg

Every color makes objects near it take on the antagonistic or complementary color.

From Project Gutenberg

Each one of a pair enhances the effect of its complementary when the two colors are brought close together.

From Project Gutenberg

If colored disks not complementary are mixed by rotation on a motor, they produce an intermediate color.

From Project Gutenberg

Related Words

• integral
• interdependent
• reciprocal

Complementary Vs. Complimentary

What’s the difference between complementary and complimentary?

Complementary is an adjective used to describe something that complements something else—goes along with it and serves to make it better or complete it (as in complementary colors). Complimentary is an adjective that can describe something intended to be a compliment—a comment that expresses praise or admiration of someone (as in a complimentary remark). It can also be used to mean that something is given for free, as in I hope we get complimentary snacks on this flight.

Since the primary senses of both words are generally used in positive contexts, it can be easy to confuse them.

The easiest way to remember the difference is that complementary often involves something that completes something else, and complete also starts with c-o-m-p-l-e. On the other hand, you can remember that complimentary is spelled with an i because compliments are something that I like to get (and give). Nice shirt, by the way.

Here’s an example of complementary and complimentary used correctly in the same sentence.

Example: Sometimes, when the chef overhears complimentary feedback about a dish, she sends out a complimentary bottle of wine—one that’s complementary to the rest of the meal, of course.

Want to learn more? Read about the difference between compliment and complement.

Quiz yourself on complementary vs. complimentary!

Should complementary or complimentary be used in the following sentence?

My comment was meant to be _____—I really do like your shoes!