supplementary
Americanadjective
noun
plural
supplementariesadjective
noun
Other Word Forms
- nonsupplementary adjective
- presupplementary adjective
- supplementarily adverb
- unsupplementary adjective
Etymology
Origin of supplementary
First recorded in 1660–70; supplement + -ary
Explanation
Supplementary is a little something extra to fill in a gap, like when your teacher suggests supplementary reading material that you may or may not get around to checking out. Supplementary can be an important part of something or just extra support. The word supplement comes from the Latin supplementum for "something added to fix a deficiency" and the suffix -ary means "connected with." Put them together and you have something connected with filling in. The supplementary support of digging a moat around your sand castle might save it from a wave, but that supplementary reading on your syllabus isn't required (although it might save your grade).
Vocabulary lists containing supplementary
The Giver
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The SAT: Language of the Test, List 6
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The New SAT: The Language of the Test
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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.
Puppetry, it turned out, moved from a supplementary expertise to Ortiz’s prime artistic strength.
From Los Angeles Times • Apr. 7, 2026
The weak growth "implies that the large supplementary budget passed at the end of November provided no boost to public spending last quarter just yet", Marcel Thieliant at Capital Economics said.
From Barron's • Feb. 16, 2026
Oil and gas firms operating in the North Sea pay a 30% corporation tax on their profits and a supplementary 10% rate on top of that.
From BBC • Jan. 21, 2026
Edesia’s latest product is a supplementary food for infants in the first two years to make sure they get all the nutrients they need.
From MarketWatch • Dec. 24, 2025
The nets were designed to leach condensation out of the cool night air, and were an important supplementary source of water in the Elmuthaleth.
From "Strange the Dreamer" by Laini Taylor
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.
