complementary

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

adjective

1. forming a complement; completing.

2. complementing each other.

noun

plural

complementaries 

1. complementary color.

complementary

/ ˌkɒmplɪˈmɛntərɪ, -trɪ /

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

Other Word Forms

• complementariness noun
• uncomplementary adjective
• complementarily adverb

Word History and Origins

Origin of complementary¹

First recorded in 1590–1600; complement + -ary

Example Sentences

"As a rule, experiments in high-energy physics have different designs even if they have the same science goal. Joint analyses allow us to use complementary features of these designs."

Read more on Science Daily

And the firm has been developing a third, complementary business that it might take public, too.

Read more on The Wall Street Journal

In reality, they offer complementary services, and this latest partnership underscores that.

Read more on Barron's

In the technical challenge, bakers were asked to make a shortcrust base with a set white chocolate ganache, topped with their choice of complementary ingredients.

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"The military pressure we applied over the past two years, together with complementary diplomatic measures, constitute a victory over Hamas," Zamir said in a televised statement.

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Related Words

• integral 
• interdependent 
• reciprocal 

When To Use

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.