complementary
Americanadjective
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acting as or forming a complement; completing
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forming a satisfactory or balanced whole
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forming a mathematical complement
sine and cosine are complementary functions
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maths logic (of a pair of sets, etc) mutually exclusive and exhaustive, each being the complement of the other
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(of genes) producing an effect in association with other genes
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involving or using the treatments and techniques of complementary medicine
Usage
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.
Other Word Forms
- complementarily adverb
- complementariness noun
- uncomplementary adjective
Etymology
Origin of complementary
First recorded in 1590–1600; complement + -ary
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Anne Marie, a beauty and complementary therapist with her own successful business, was at a pub in East Kilbride, South Lanarkshire, with her cousins on the night of the incident.
From BBC • Mar. 30, 2026
Over four seasons at Purdue, Smith has transformed from a complementary player whose job was to set up the Boilermakers’ big men to an All-American who will leave as one of college basketball’s all-time playmakers.
From The Wall Street Journal • Mar. 19, 2026
NOvA's longer distance through Earth and T2K's shorter but more intense beam provide complementary strengths, allowing scientists to compare and refine their measurements with exceptional precision.
From Science Daily • Mar. 3, 2026
“By bringing together these world-class studios, our complementary streaming platforms, and the extraordinary talent behind them, we will create even greater value for audiences, partners and shareholders,” he said.
From Los Angeles Times • Feb. 27, 2026
They read about the phenomenon of simultaneous contrast of colors, about complementary colors.
From "Vincent and Theo: The Van Gogh Brothers" by Deborah Heiligman
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
