supplement
Americannoun
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something added to complete a thing, supply a deficiency, or reinforce or extend a whole.
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a part added to a book, document, etc., to supply additional or later information, correct errors, or the like.
- Synonyms:
- postscript, epilogue, addendum
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a part, usually of special character, issued as an additional feature of a newspaper or other periodical.
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Geometry. the quantity by which an angle or an arc falls short of 180° or a semicircle.
verb (used with object)
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to complete, add to, or extend by a supplement.
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to form a supplement or addition to.
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to supply (a deficiency).
noun
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an addition designed to complete, make up for a deficiency, etc
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a section appended to a publication to supply further information, correct errors, etc
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a magazine or section inserted into a newspaper or periodical, such as one with colour photographs issued every week
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geometry
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either of a pair of angles whose sum is 180°
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Abbreviation: sup. supp. an arc of a circle that when added to another arc forms a semicircle
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verb
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
Inflected Forms
Nouns
Participles
Conjugated Forms
Present
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supplementsimple
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supplementssimple
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have supplementedperfect
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has supplementedperfect
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am supplementingprogressive
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are supplementingprogressive
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is supplementingprogressive
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have been supplementingperfect progressive
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has been supplementingperfect progressive
Past
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supplementedsimple
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had supplementedperfect
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was supplementingprogressive
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were supplementingprogressive
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had been supplementingperfect progressive
Future
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.
Vocabulary lists containing supplement
Richard Nixon's "Checkers" Speech (1952)
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Nutrition - Introductory
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Nutrition - Middle School
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
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
Creatine is widely known as a supplement used by athletes and bodybuilders to improve strength and performance.
From Science Daily ● Jul. 8, 2026
Oliver took odd jobs around town to supplement her income, including for Norman Mailer—according to the film, she typed “The Executioner’s Song,” his Pulitzer Prize-winning epic of 1979.
From The Wall Street Journal ● Jul. 2, 2026
Scarlett was carrying a large picture book, and she sat next to her mother on the green bench near the gates, and she read her book while her mother inspected an educational supplement.
From "The Graveyard Book" by Neil Gaiman
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
Nowadays, more than 30,000 people attend their festival every year, held in London and Birmingham, with exhibitors selling organic food, crystals, homemade products and supplements.
From BBC ● Jul. 12, 2026
Kyle Gordy does not drink alcohol or smoke, takes 30 supplements a day, eats only organic food and drinks nothing but filtered water.
From BBC ● Jul. 5, 2026
Those who took DHA supplements performed no better on cognitive tests than participants who received a placebo.
From Science Daily ● Jun. 29, 2026
Newspapers could now print illustrations cheaply and well, and they all ran illustrated supplements on the theft.
From "The Mona Lisa Vanishes" by Nicholas Day
Portland supplemented the federal construction money with local dollars, creating incentives that were hard to turn down.
From Salon ● Jul. 4, 2026
The director’s moaning score here, supplemented with sputtering engines and clanking chains, underline the movie’s ghost-story vibe — the sense that poor Nick is both alive and dead.
From Los Angeles Times ● Jun. 19, 2026
The wall will be supplemented by electronic surveillance and other devices, which would be installed by "about July, maybe at the latest August 2028," Scott said.
From Barron's ● Jun. 9, 2026
Troha then gave another group of mice chow supplemented with methionine.
From Science Daily ● Jun. 1, 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
Culhane recommends faster approval of SSI benefits and supplementing that income with additional sources of rental assistance.
From Los Angeles Times ● Jul. 8, 2026
Rather than replacing existing recommendations, Dr. Macdonald suggests supplementing them with guidance focused on what he calls "optimal health outcomes."
From Science Daily ● Jun. 23, 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
They brought state, national and international news, supplementing our own Scripps-Howard services.
From The Wall Street Journal ● Feb. 8, 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
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
