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

Only 3.6% of participants taking the supplement left the study, compared with 21% of those in the physiotherapy group.

From Science Daily ● Jul. 25, 2026

Together they run the company Immortals, which includes their Blueprint supplement and product line, access to prescription medicine and a concierge medical practice.

From The Wall Street Journal ● Jul. 13, 2026

The Ojai will supplement Waymo’s fleet of Jaguar I-Paces, the company said.

From Los Angeles Times ● Jul. 9, 2026

To supplement what I did have, I would show up to interviews with self-published articles and story pitches that might appeal to the employer I was interviewing with.

From MarketWatch ● Jul. 8, 2026

His famous equation, E=mc2, did not appear with the paper, but came in a brief supplement that followed a few months later.

From "A Short History of Nearly Everything" by Bill Bryson

But having a strong farm system supplements big spending.

From Los Angeles Times ● Jul. 27, 2026

Three years ago, the FDA placed restrictions on 14 peptides over safety risks, meaning they now fall somewhere between the unregulated world of supplements and the highly structured process of testing new drugs.

From MarketWatch ● Jul. 23, 2026

Then she tried Johnson’s antiaging “protocol,” eating just 1,700 calories a day and taking 60 supplements.

From The Wall Street Journal ● Jul. 13, 2026

Other protocols promoted by influencers without medical evidence have included certain supplements, red light therapy, and donating blood to "filter out" microplastics.

From BBC ● Jul. 11, 2026

Bookshelves lined the far wall, filled with role-playing game supplements and back issues of Dragon magazine.

From "Ready Player One: A Novel" by Ernest Cline

"If you look at what our adversaries are building, they're also building significantly large platforms - aircraft, ships, submarines. And they're supplemented by some of these unmanned capabilities."

From BBC ● Jul. 23, 2026

Portland supplemented the federal construction money with local dollars, creating incentives that were hard to turn down.

From Salon ● Jul. 4, 2026

Troha then gave another group of mice chow supplemented with methionine.

From Science Daily ● Jun. 1, 2026

An internal sprinkler system supplemented by unmanned ground sprinklers helped stabilize temperatures around 90 degrees, division chief and hazardous materials program manager Nick Freeman said.

From Los Angeles Times ● May 23, 2026

“St. Martin’s in the Fields it used to be called,” supplemented the old man, “though I don’t recollect any fields anywhere in those parts.”

From "1984" by George Orwell

Proponents said it can elevate instruction, narrow the digital divide, help pupils with language barriers and other needs—while often supplementing, not replacing, core curriculum.

From The Wall Street Journal ● Jun. 21, 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

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

OpenAI and Anthropic are supplementing their FDE teams by partnering with consulting firms.

From MarketWatch ● Apr. 4, 2026

The Bible has much to teach, yet professors must use it judiciously, supplementing it with other sources, when they teach ancient Middle Eastern history.

From "1491" by Charles C. Mann

Related Words

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