supplement
Americannoun
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supplements
plural
-
something added to complete a thing, supply a deficiency, or reinforce or extend a whole.
-
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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supplements,
present (3rd person singular)
-
supplemented,
past participle, past
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supplementing
present participle
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to complete, add to, or extend by a supplement.
-
to form a supplement or addition to.
-
to supply (a deficiency).
noun
-
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
-
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
-
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
-
is supplementingprogressive
-
have been supplementingperfect progressive
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has been supplementingperfect progressive
Past
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supplementedsimple
-
had supplementedperfect
-
was supplementingprogressive
-
were supplementingprogressive
-
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:
When there was an issue, I scheduled seminars, makeup sessions and phone office hours at different times to supplement the meetings and assignments.
From Salon ● Aug. 24, 2026
If Americans know magnesium at all, it is as a dietary supplement or as “mag wheels” for car enthusiasts.
From The Wall Street Journal ● Aug. 24, 2026
The new findings suggest that a yeast-based supplement could potentially help restore some of that lost immune activity.
From Science Daily ● Aug. 22, 2026
Ode staff helps supplement Baker Tilly’s small internal software engineering team.
From The Wall Street Journal ● Aug. 21, 2026
In connection with the new arrangement, Lawrence received approval for his expanded Alpha II plant, which would supplement the feed from the diffusion process in a final push to produce uranium enriched to weapon-grade.
From "Big Science" by Michael Hiltzik
They did this either by giving dietary supplements containing nitrate and iron or by administering synthetically produced DNIC.
From Science Daily ● Aug. 24, 2026
So, what do supplements actually do and why do athletes take them?
From BBC ● Aug. 20, 2026
One option is Hawaii’s small but promising ocean-tech industry, which includes firms that repair cargo ships, make sensors to detect floods, breed commercial shellfish or make livestock supplements from seaweed.
From The Wall Street Journal ● Aug. 20, 2026
Another is the existence of relatively new statutes that support growing schools of the Atlantic menhaden, an oily fish with a variety of industrial uses like commercial bait and omega-3 supplements.
From Barron's ● Aug. 18, 2026
She stopped to browse through the shelf of role-playing game supplements.
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
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
Its sales are now supplemented by mNexspike, a next-generation vaccine designed for the current respiratory virus season.
From Barron's ● May 13, 2026
Modern salaries, of course, are supplemented by the employer’s pension contributions and other charges, so they cannot be directly compared with seventeenth-century salaries.
From "The Invention of Science" by David Wootton
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
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
Meanwhile masons and carpenters were at work building a large and stately new boathouse, Haus West, just east of the permanent grandstands, supplementing two large existing boathouses, Haus Mitte and Haus Ost.
From "The Boys in the Boat: Nine Americans and Their Epic Quest for Gold at the 1936 Berlin Olympics" by Daniel James Brown
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.
