supplement

American  

[suhp-luh-muhnt, suhp-luh-ment] / ˈsʌp lə mənt, ˈsʌp ləˌmɛnt /

noun

• supplements
  plural

1. something added to complete a thing, supply a deficiency, or reinforce or extend a whole.

2. a part added to a book, document, etc., to supply additional or later information, correct errors, or the like.

   Synonyms:

   postscript, epilogue, addendum

3. a part, usually of special character, issued as an additional feature of a newspaper or other periodical.

4. Geometry. the quantity by which an angle or an arc falls short of 180° or a semicircle.

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verb (used with object)

• supplements,
  present (3rd person singular)
• supplemented,
  past participle,  past
• supplementing
  present participle

1. to complete, add to, or extend by a supplement.

2. to form a supplement or addition to.

3. to supply (a deficiency).

supplement British  

noun

1. an addition designed to complete, make up for a deficiency, etc

2. a section appended to a publication to supply further information, correct errors, etc

3. a magazine or section inserted into a newspaper or periodical, such as one with colour photographs issued every week

4. geometry

   1. either of a pair of angles whose sum is 180°

   2. Abbreviation: sup.   supp.  an arc of a circle that when added to another arc forms a semicircle

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verb

1. (tr) to provide a supplement to, esp in order to remedy a deficiency

Usage

What does supplement mean? A supplement is an addition to something that completes it or makes up for a shortcoming, as in He takes vitamin supplements to make up for his vitamin C deficiency. A supplement is also an addition to a book that provides important information or corrects errors. In this sense, supplement can be confused with the words appendix and index. An appendix gives additional information, such as charts and graphs, but the book or document would be considered complete without it. An index is an alphabetical list of names or topics with page numbers that helps you find something specific in the book, such as all the references to John Wilkes Booth in a biography of Abraham Lincoln. As a verb, supplement means to add to something, as in Tameka sold paintings to supplement her income. In this sense, supplement can be confused with the word complement. Both words mean to add something, but to complement means to add something to make up for a missing piece or element, while to supplement is to add extra information. Example: The company built a new roller coaster to supplement its original roller coaster, which always has a long line.  

Synonym Usage

See appendix. See complement.

Other Word Forms

Derived Forms

• supplementation
  noun
• supplementer
  noun
• unsupplemented
  adjective
• well-supplemented
  adjective

Inflected Forms

Nouns

• supplements
  plural

Participles

• supplementing
  present
• supplemented
  past

Conjugated Forms

Present

• supplement
  simple
• supplements
  simple
• have supplemented
  perfect
• has supplemented
  perfect
• am supplementing
  progressive
• are supplementing
  progressive
• is supplementing
  progressive
• have been supplementing
  perfect progressive
• has been supplementing
  perfect progressive

Past

• supplemented
  simple
• had supplemented
  perfect
• was supplementing
  progressive
• were supplementing
  progressive
• had been supplementing
  perfect progressive

Future

• will supplement
  simple
• will have supplemented
  perfect
• will be supplementing
  progressive
• will have been supplementing
  perfect progressive

Etymology

Origin of supplement

First recorded in 1350–1400; Middle English, from Latin supplēmentum “that by which anything is made full,” equivalent to sup- sup- + plē- (stem of plēre “to fill”; see full ¹) + -mentum -ment

Explanation

A supplement is something added to something else. Nutritional supplements add vitamins and minerals to the ones already included in the food you eat. If a zombie army wants to increase its ranks but is running out of bodies, it might supplement its troops with mummies. If the zombies put out their manifesto and then realize they left out an important point, they might supplement the manifesto with a press release. That press release could also be referred to as a supplement.

Example Sentences

See Examples For:

supplement supplements supplemented supplementing

Some items, like the chicken tenders with ranch crème fraîche, can receive a caviar supplement.

From Los Angeles Times ● Sep. 17, 2026

To replace it, there’s Social Security — but most people supplement that from their own pockets.

From MarketWatch ● Sep. 8, 2026

Treasury says the armed forces, including the Islamic Revolutionary Guard Corps, use dedicated companies and shadow-fleet networks to sell crude and supplement their budgets.

From The Wall Street Journal ● Sep. 7, 2026

Tyrosine is widely sold as a dietary supplement and is often promoted for improving focus, alertness, and mental performance.

From Science Daily ● Sep. 6, 2026

The idea that America required a second weapons laboratory to supplement Los Alamos originated with Edward Teller and was driven by two factors.

From "Big Science" by Michael Hiltzik

Ulta Beauty expanded its wellness strategy by adding a selection of Midi Health supplements online and in stores.

From The Wall Street Journal ● Sep. 15, 2026

"There's been a lot of interest in using antioxidant supplements for air pollution in general," she said.

From BBC ● Sep. 12, 2026

The Gambia supplements its own generation with imported electricity, including supplies from Guinea and neighbouring Senegal.

From BBC ● Sep. 9, 2026

To explore that possibility, the team added plasmalogens to the diets of aged mice and examined how the supplements affected both their behavior and their bodies.

From Science Daily ● Sep. 4, 2026

For 2,000 years those founder crops served only as minor dietary supplements while eastern U.S.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

“Over the years, my mother and I have supplemented his income.”

From The Wall Street Journal ● Sep. 14, 2026

Over the years, my mother and I have supplemented his income.

From MarketWatch ● Sep. 10, 2026

Voting-rights groups supplemented a parallel suit to challenge the rule as well.

From Slate ● Aug. 31, 2026

The shortfall in power is usually covered by solar and wind during the hot, windy daytimes - but traditional coal- and gas-powered generation will have to be supplemented by imports during the evenings.

From BBC ● Aug. 13, 2026

European weapons were steel swords, lances, and daggers, supplemented by small firearms and artillery, while body armor and helmets were also made of solid steel or else of chain mail.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

The ratio was changed a bit—ground ops were supplementing the air war, not the other way around; but still the ground ops were necessary.

From Slate ● Jul. 30, 2026

Scientists still do not know whether boosting Menin or supplementing with D-serine could safely slow aging or improve cognition in people.

From Science Daily ● May 24, 2026

The Dodgers are supplementing where they can, picking up three pitchers cut by their former clubs.

From Los Angeles Times ● May 19, 2026

But some experts suggest the solar-powered streetlights are best suited to supplementing large data centres, not replacing them: there will still be a need for their concentrated computing power and efficiencies of scale.

From BBC ● May 1, 2026

The mighty dinos stood in military formation, each with additional armor supplementing its already fierce horned head shield and thick hide.

From "Dactyl Hill Squad" by Daniel José Older

Related Words

• augment
• build up
• buttress
• complement
• enhance
• enrich
• fill out
• fortify
• improve
• reinforce
• strengthen
• subsidize