complement

[ noun kom-pluh-muhnt; verb kom-pluh-ment ]

/ noun ˈkɒm plə mənt; verb ˈkɒm pləˌmɛnt /

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See synonyms for: complement / complemented / complementing / complements on Thesaurus.com

noun

something that completes or makes perfect: A good wine is a complement to a good meal.

the quantity or amount that completes anything: We now have a full complement of packers.

either of two parts or things needed to complete the whole; counterpart.

full quantity or amount; complete allowance.

the full number of officers and crew required on a ship.

Grammar.

a word or group of words that completes a grammatical construction in the predicate and that describes or is identified with the subject or object, as small in The house is small or president in They elected her president.Compare object complement, subject complement.
any word or group of words used to complete a grammatical construction, especially in the predicate, including adverbials, as on the table in He put it on the table, infinitives, as to go in They are ready to go, and sometimes objects, as ball in He caught the ball.

Geometry. the quantity by which an angle or an arc falls short of 90° or a quarter of a circle.Compare supplement (def. 4).

Also called absolute complement. Mathematics. the set of all the elements of a universal set not included in a given set.

Music. the interval that completes an octave when added to a given interval.

Immunology.

a system in vertebrate blood of 12 or more proteins that react in a cascade to a cell displaying immune complexes or foreign surfaces, acting in various combinations to coat the cell and promote phagocytosis, make holes in the cell wall, or enhance the inflammatory response.
any of the proteins in the complement system, designated C1, C2, etc.

complementary color.

verb (used with object)

to complete; form a complement to: This belt complements the dress better than that one.

Obsolete. to compliment.

verb (used without object)

Obsolete. to compliment.

QUIZ

THINGAMABOB OR THINGUMMY: CAN YOU DISTINGUISH BETWEEN THE US AND UK TERMS IN THIS QUIZ?

Do you know the difference between everyday US and UK terminology? Test yourself with this quiz on words that differ across the Atlantic.

Question 1 of 7

In the UK, COTTON CANDY is more commonly known as…

candystring

candyfloss

candypuff

TAKE THE QUIZ TO FIND OUT

Origin of complement

First recorded in 1350–1400; Middle English, from Latin complēmentum “something that completes,” equivalent to complē(re) “to fill, fill up” + -mentum noun suffix; see origin at complete,-ment

synonym study for complement

12. Complement, supplement both mean to make additions to something. To complement is to provide something felt to be lacking or needed; it is often applied to putting together two things, each of which supplies what is lacking in the other, to make a complete whole: Two statements from different points of view may complement each other. To supplement is merely to add to: Some additional remarks may supplement his address.

words often confused with complement

Complement and compliment, which are pronounced alike and originally shared some meanings, have become separate words with entirely different meanings. As a noun, complement means “something that completes or makes perfect”: The rare old brandy was a perfect complement to the delicious meal. As a verb, complement means “to complete”: A bright scarf complements a dark suit. The noun compliment means “an expression of praise, commendation, or admiration”: The members paid her the compliment of a standing ovation. The verb compliment means “to pay a compliment to”: Everyone complimented him after the recital.

OTHER WORDS FROM complement

com·ple·ment·er, noun

WORDS THAT MAY BE CONFUSED WITH complement

1. complement , supplement (see synonym study at the current entry)2. complement , compliment (see confusables note at the current entry)

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use complement in a sentence

The Heat executive also emphasized that the screenings are a complement to all the other steps being taken to keep guests and employees from catching the virus, should it make its way into the arena.
Miami Heat to use coronavirus-sniffing dogs to allow some fans back into arena|Des Bieler|January 22, 2021|Washington Post
He said the band’s usual 80-member inauguration complement will be fewer than 60 this year.
The Marine Band has played at every inauguration since Jefferson. It’s one tradition that will carry on this year.|Michael Ruane|January 19, 2021|Washington Post
The deal may also prove that some of Alexion’s R&D around the complement system will dovetail with AstraZeneca’s heavy investment into a class of immunotherapy cancer treatments known as PARP inhibitors.
Why shareholders had a severe adverse reaction to AstraZeneca’s Alexion deal|Jeremy Kahn|December 14, 2020|Fortune
This cornbread dressing is not only delicious with turkey, but is a tasty complement to a holiday ham.
Hints From Heloise: Washing wine glasses|Heloise Heloise|November 11, 2020|Washington Post

“Digital wallets are a natural complement to all forms of digital currency,” said Schulman, adding that PayPal is in close talks with central banks and regulators to explore new uses for these wallets.
PayPal plans a much wider embrace of cryptocurrency, including Venmo use|Jeff|November 2, 2020|Fortune
Complementing him, she added Uri Sagi, a well-respected former leader of military intelligence.
The Return Of Labor|Brent E. Sasley|October 26, 2012|DAILY BEAST
Arizona contends that it is simply complementing federal law.
Supreme Court Takes Up Controversial Arizona Immigration Law|Laura Colarusso|April 24, 2012|DAILY BEAST
I had now that rare complementing pair, a legend and its historical foundation.
Lippincott's Magazine of Popular Literature and Science, Vol. 12, No. 32, November, 1873|Various
This theory seems true enough when we remember that mankind has three languages, each complementing the other.
Critical & Historical Essays|Edward MacDowell
Complementing the work of these men and women was the opinion of the American serviceman himself.
Integration of the Armed Forces, 1940-1965|Morris J. MacGregor, Jr.
Corruption, theft and graft were tolerated by the state as means of complementing income.
After the Rain|Sam Vaknin
Candace did not know how long the reading and the music had been going on, each complementing the other.
A Little Country Girl|Susan Coolidge

British Dictionary definitions for complement

complement

noun (ˈkɒmplɪmənt)

a person or thing that completes something

one of two parts that make up a whole or complete each other

a complete amount, number, etc (often in the phrase full complement)

the officers and crew needed to man a ship

grammar

a noun phrase that follows a copula or similar verb, as for example an idiot in the sentence He is an idiot
a clause that serves as the subject or direct object of a verb or the direct object of a preposition, as for example that he would be early in the sentence I hoped that he would be early

maths the angle that when added to a specified angle produces a right angle

logic maths the class of all things, or of all members of a given universe of discourse, that are not members of a given set

music the inverted form of an interval that, when added to the interval, completes the octavethe sixth is the complement of the third

immunol a group of proteins in the blood serum that, when activated by antibodies, causes destruction of alien cells, such as bacteria

verb (ˈkɒmplɪˌmɛnt)

(tr) to add to, make complete, or form a complement to

Word Origin for complement

C14: from Latin complēmentum, from complēre to fill up, from com- (intensive) + plēre to fill

undefined complement

Avoid confusion with compliment

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for complement

complement

[ kŏm′plə-mənt ]

A group of proteins in blood serum that interact systematically as part of the body's immune response to destroy disease-causing antigens, especially bacteria. Complement proteins interact with antibodies and other chemical substances to cause the disintegration of foreign cells and enhance other immune functions such as phagocytosis.

A complementary color.

complement

Origin of complement

synonym study for complement

words often confused with complement

OTHER WORDS FROM complement

WORDS THAT MAY BE CONFUSED WITH complement

Words related to complement

How to use complement in a sentence

British Dictionary definitions for complement

Word Origin for complement

undefined complement

Scientific definitions for complement