com·​ple·​ment | \ ˈkäm-plə-mənt How to pronounce complement (audio) \

Definition of complement

 (Entry 1 of 2)

1a : something that fills up, completes, or makes better or perfect The scarf is a perfect complement to her outfit.
b(1) : the full quantity, number, or assortment needed or included … the usual complement of eyes and ears …— Francis Parkman … after several more minutes of waiting, the full complement of runners was sent off by the starter's pistol.— Craig Neff
(2) : the whole force or personnel of a ship
c : one of two mutually completing parts : counterpart She is a kind of complement to me, and we get on famously.— Flannery O'Connor
2 : an added word or expression by which a predication is made complete (such as president in "they elected him president" and beautiful in "he thought her beautiful")
3a : the angle or arc that when added to a given angle or arc equals a right angle in measure
b : the set of all elements that do not belong to a given set and are contained in a particular mathematical set containing the given set
c : a number that when added to a certain number of the same sign yields a number with the digit 1 as the significant digit farthest to the left and the digit 0 in every other digit place used especially in assembly language programming
4 : the musical interval required with a given interval to complete the octave
5 : the thermolabile group of proteins in normal blood serum and plasma that in combination with antibodies causes the destruction especially of particulate antigens (such as bacteria and foreign blood corpuscles)


com·​ple·​ment | \ ˈkäm-plə-ˌment How to pronounce complement (audio) \
complemented; complementing; complements

Definition of complement (Entry 2 of 2)

transitive verb

1 : to complete or enhance by providing something additional : to be complementary to The illustrations complement the text.
2 obsolete : compliment

intransitive verb

obsolete : to exchange formal courtesies

Illustration of complement

Illustration of complement


complement 3a: ACB right angle, ACD complement of DCB (and vice versa), AD complement of DB (and vice versa)

In the meaning defined above

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Synonyms for complement

Synonyms: Noun

Synonyms: Verb

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Is it complement or compliment?

Today there is no overlap between the meanings of complement and compliment, as either nouns or verbs, but their similar spellings and pronunciations make them prime candidates for confusion. Despite the difference in their meanings, both complement and compliment have roots in the Latin word complēre which means “to complete.” Complement remains true to that origin in its spelling and in its meanings that have to do with completing or completion. Keep that connection in mind and there should be no question as to whether complement or compliment is the correct word to use in a given context.

Examples of complement in a Sentence

Noun With the loss of just one American and four Japanese carriers, including their complements of aircraft and many of their superbly trained fliers …  , Midway … put the Japanese navy at a disadvantage from which it never recovered. — David M. Kennedy, Atlantic, March 1999 Exact observation of the outer world was the complement to a literal reading of Scripture. — Garry Wills, Under God, 1990 The usual complement of Kremlin guards was about, one company of infantry with light arms. — Tom Clancy, Red Storm Rising, 1986 His faults are accepted as the necessary complement to his merits. — W. Somerset Maugham, Moon and Sixpence, 1919 The scarf is a perfect complement to her outfit. a full complement of farm animals her usual complement of attendants a ship's complement of officers “President” in “they elected her president” and “to work” in “he wants to work” are different kinds of complements. Verb Carrots often work even better than sticks, so I propose a skinny subsidy to complement the fat tax. — Jonathan Rauch, Atlantic, December 2002 The love of Bottom's bottomless vision at least complements, if it does not transcend, the rational love of Theseus. — Frank Kermode, Shakespeare's Language, 2000 … his ice-blue Appalachian eyes glint through horn-rimmed glasses, which complement his salt-and-pepper beard. — Henry Louis Gates, Jr., New Yorker, 19 June 1995 … lively photographs, illustrations and cartoons designed to complement the meanings of the poems and give a leg-up to the imagination. — Carol Ann Duffy, Times Literary Supplement, 4-10 Dec. 1987 The shirt complements the suit nicely. a delicious dinner complemented by a splendid dessert The soup and salad complement each other well.
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Recent Examples on the Web: Noun Those who missed the order deadline were still able to munch on the full complement of festival foods from a variety of vendors. cleveland, 27 Sep. 2021 Getting Daniels back at full strength and providing him a full complement of receivers would help the Bulldogs avoid relying primarily on an outstanding defense to get past opponents such as Arkansas, Auburn and Florida. Paul Myerberg, USA TODAY, 24 Sep. 2021 But without a full complement of receivers during training camp and the preseason, the next evolution remains a mystery. Jonas Shaffer,, 2 Sep. 2021 But the real excitement was the greeting Colbert received from the full complement of acolytes in the Ed Sullivan Theater. Bill Carter For Cnn Business Perspectives, CNN, 25 June 2021 According to a major league source, multiple teams have invited the righthander to predraft workouts in front of a full complement of their evaluators., 21 June 2021 The indoor bar will have 12 beer taps, selling local and regional brews, as well as a full complement of alcoholic beverages. Susan Dunne,, 18 June 2021 Reflective surfaces such as mirrors, glass, and metallic finishes are a natural complement to jewel tones, helping to play up the glam look, Yeo says. Jessica Bennett, Better Homes & Gardens, 9 June 2021 The Excelsior Band’s full complement of musicians consists of trumpet players, a tuba, bass drum, snare drum, saxophone players and a trombone player. J.d. Crowe |, al, 21 May 2021 Recent Examples on the Web: Verb Getting in the Christmas spirit starts with decorating your home with cozy accents and accessories that will complement your existing seasonal decor. Sanah Faroke, Better Homes & Gardens, 11 Oct. 2021 The wild combination starts off sweet and then offers a savory finish thanks to bitter cranberry flavors that complement the coffee. Tirion Morris, The Arizona Republic, 8 Oct. 2021 In fact, James Bond, despite his unique skills, rely on a variety of allies that complement his skill set. Thomas Roulet, Forbes, 3 Oct. 2021 The space is designed to include bright interiors that complement the custom millwork throughout, according to Assouline. Linda Marx,, 20 Sep. 2021 Decorative flourishes include a brick fireplace and indoor pillars that complement such contemporary conveniences as a wet bar, walk-in closets and whole-house generator. Mary Carole Mccauley,, 1 Sep. 2021 When paired with its rolling hills and soil content, the low-pressure systems combine to create sunny days and cool nights that complement its granitic, mineral-rich soil — all of which help the grapes to retain higher acid content and tannins. Giovanna Caravetta, Travel + Leisure, 14 Aug. 2021 Other players that will complement Roberts are Tuione Tausinga and Kalausa Fonua, who is a captain of the team and returning from an ACL injury. Alex Vejar, The Salt Lake Tribune, 13 Aug. 2021 Publicly, Macron presented the movement as a personal project that would complement his work as minister. Isaac Chotiner, The New Yorker, 12 Aug. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'complement.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of complement


14th century, in the meaning defined at sense 1a


1602, in the meaning defined at intransitive sense

History and Etymology for complement

Noun and Verb

Middle English, from Latin complementum, from complēre to fill up, complete, from com- + plēre to fill — more at full

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Time Traveler for complement

Time Traveler

The first known use of complement was in the 14th century

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Dictionary Entries Near complement




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Statistics for complement

Last Updated

13 Oct 2021

Cite this Entry

“Complement.” Dictionary, Merriam-Webster, Accessed 17 Oct. 2021.

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More Definitions for complement



English Language Learners Definition of complement

 (Entry 1 of 2)

: something that completes something else or makes it better
: the usual number or quantity of something that is needed or used
: a word or group of words added to a sentence to make it complete



English Language Learners Definition of complement (Entry 2 of 2)

: to complete something else or make it better


com·​ple·​ment | \ ˈkäm-plə-mənt How to pronounce complement (audio) \

Kids Definition of complement

 (Entry 1 of 2)

1 : something that makes whole or better The cool salad was the perfect complement to the spicy dish.
2 : the number or quantity of something that is needed or used the ship's complement of crew


com·​ple·​ment | \ ˈkäm-plə-ˌment How to pronounce complement (audio) \
complemented; complementing

Kids Definition of complement (Entry 2 of 2)

: to serve as something necessary to make whole or better Find a hat that complements your costume.


com·​ple·​ment | \ ˈkäm-plə-mənt How to pronounce complement (audio) \

Medical Definition of complement

1 : a group or set (as of chromosomes or DNA) that is typical of the complete organism or one of its parts — see chromosome complement
2 : a complementary color
3 : the thermolabile group of proteins in normal blood serum and plasma that in combination with antibodies causes the destruction especially of particulate antigens (as bacteria and foreign blood corpuscles)

More from Merriam-Webster on complement

Nglish: Translation of complement for Spanish Speakers

Britannica English: Translation of complement for Arabic Speakers Encyclopedia article about complement


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