What does complementary mean?
Complementary describes things that combine so as to complete, enhance, or balance each other — qualities or parts that, taken together, form a satisfying whole. Two people with complementary skills each bring different strengths that fill gaps in the other's abilities; complementary colors sit opposite each other on the color wheel and intensify one another when placed side by side. The word carries a positive connotation of harmony, mutual benefit, and completeness, and appears often in discussions of teamwork, design, science, and health. It should not be confused with its near-homophone "complimentary," which relates to praise or something given free. Derived ultimately from the Latin complēre, meaning "to fill up or complete," complementary literally captures the idea of filling out a whole.
adjectiveCombining in such a way as to enhance or emphasize the qualities of each other; forming a complete or satisfying whole when taken together. In mathematics and genetics, it also describes things that together make up a whole, such as angles that sum to 90 degrees.
- Serving to complete or enhance one another; combining well to form a whole.
- (Of angles) summing to 90 degrees.
- (Of DNA strands or base pairs) capable of precise pairing according to the base-pairing rules.
- Relating to alternative or adjunct therapies used alongside conventional medicine.
"Their skills were highly complementary: she handled the design while he managed the engineering."
"The wine list was designed with complementary pairings for each course."
"In right triangles, the two acute angles are always complementary."
One little letter separates two very different compliments: complementary things fit together perfectly — complimentary ones cost you nothing.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of complementary
Complementary derives from the Latin complementum, meaning "that which fills up or completes," itself from complēre ("to fill up"), formed from com- ("together") and plēre ("to fill"). English adopted both the noun complement and the adjective complementary in the early modern period, the adjective becoming established by the mid-seventeenth century. It shares this Latin root with words like complete, completion, plenary, and accomplish. Notably, the unrelated-looking "compliment" traces back to the same Latin verb via Italian, making the two near-spellings distant cousins.
Related word forms
How complementary is actually used
Neutral to positive connotation; common in formal, scientific, design, and business writing. Frequently used in the phrase "complementary medicine," which refers to therapies used alongside conventional treatment (as opposed to "alternative medicine," which replaces it).
Easily confused with complementary
"Complementary" means things that complete or enhance each other, while "complimentary" means given free of charge or expressing praise.