complement

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

noun

1. something that completes or makes perfect:

   A good wine is a complement to a good meal.

2. the quantity or amount that completes anything:

   We now have a full complement of packers.

3. either of two parts or things needed to complete the whole; counterpart.
4. full quantity or amount; complete allowance.
5. the full number of officers and crew required on a ship.
6. Grammar.
   1. 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.
   2. 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.
7. Geometry. the quantity by which an angle or an arc falls short of 90° or a quarter of a circle. Compare supplement ( def 4 ).
8. Also called absolute complement. Mathematics. the set of all the elements of a universal set not included in a given set.
9. Music. the interval that completes an octave when added to a given interval.
10. Immunology.
    1. 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.
    2. any of the proteins in the complement system, designated C1, C2, etc.
11. complementary color.

verb (used with object)

1. to complete; form a complement to:

   This belt complements the dress better than that one.

2. Obsolete. to compliment.

verb (used without object)

1. Obsolete. to compliment.

complement

noun

1. a person or thing that completes something
2. one of two parts that make up a whole or complete each other
3. a complete amount, number, etc (often in the phrase full complement )
4. the officers and crew needed to man a ship
5. grammar
   1. a noun phrase that follows a copula or similar verb, as for example an idiot in the sentence He is an idiot
   2. 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
6. maths the angle that when added to a specified angle produces a right angle
7. 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
8. music the inverted form of an interval that, when added to the interval, completes the octave

   the sixth is the complement of the third

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

verb

1. tr to add to, make complete, or form a complement to

complement

/ kŏm′plə-mənt /

1. 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.
2. A complementary color.

Usage

See compliment

Confusables Note

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

• com·ple·ment·er noun

Word History and Origins

Origin of complement¹

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

Word History and Origins

Origin of complement¹

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

Synonym Study

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.

Example Sentences

Rusenko acknowledges that QR-code ordering may not be for everyone and notes that it is designed as a complement rather than a replacement for traditional service from a waiter.

From Fortune

As he had on Tuesday, he also explicitly made the link between having a full complement of nine justices and a potential need for the Supreme Court to rule on a disputed election result.

From Washington Post

There’s been a series of programs, intentional and targeted interventions, that really allow us now to look at the full complement of our people’s journey.

From Fortune

Face masks can be a complement to other things when other things are safely in place.

From Fortune

Their streaming ad inventory was sold in complement to their linear ad inventory.

From Digiday

Champagne, which is also acidic, offers a nice complement to anything from tuna tartare to beef bourguignon.

From The Daily Beast

They play an important role fighting next to the men because they complement one another.

From The Daily Beast

To complement brain wiring, everyone walks around with retinal cams.

From The Daily Beast

The ship is highly automated with a crew of just 142 -- compared to older ships that have a complement of about 300.

From The Daily Beast

The mini-thons will be thematically organized to complement the new episode.

From The Daily Beast

Take a case in Trigonometry—a Complement is what remains after subtracting an angle from one right-angle.

From Project Gutenberg

Her total Naval complement is 2200 officers and enlisted men of the regular Navy.

From Project Gutenberg

The French continually offers redundancy of subject or complement, but not with the relative.

From Project Gutenberg

It is the apt accompaniment of a whining tongue, the fit complement of a verjuice countenance.

From Project Gutenberg

There is no dramme of manhood to suspect,On such thin ayrie circumstance as thisMeere complement and courtship.

From Project Gutenberg

Related Words

• achieve
• integrate

Complement Vs. Compliment

What’s the difference between complement and compliment?

The word complement most commonly refers to something that goes along with something else and serves to make it better or complete it. It’s also commonly used as a verb meaning to serve as a complement in this way, as in That necklace really complements the rest of your outfit. A compliment is a comment intended to express praise or admiration of someone. Compliment is also commonly used as a verb meaning to give a compliment.

Complement has many other specific meanings, but compliment is really only used to refer to a nice comment or the action of giving one.

Since the primary senses of both words are generally used in positive contexts, it can be easy to confuse them.

The adjective form of complement is complementary, as in complementary colors. The adjective form of compliment is complimentary, which can describe something intended to be a compliment, as in complimentary remark, or it can be used to mean that something is given for free, as in I hope we get complimentary snacks on this flight.

The easiest way to remember the difference is that complement often means to complete, and complete also starts with c-o-m-p-l-e. On the other hand, compliment is spelled with an i, and compliments are something that I like to get (and give). Nice shirt, by the way.

Here’s an example of complement and compliment used correctly in the same sentence.

Example: The chef overheard the diners at one table complimenting the way the sauce complemented the fish, so she told the server to offer them a complimentary dessert.

Want to learn more? Read the full breakdown of the difference between complement and compliment.

Quiz yourself on complement vs. compliment!

Should complement or compliment be used in the following sentence?

The two singers have very different styles, but they _____ each other so well during the performance.