supplementary

American  

[suhp-luh-men-tuh-ree] / ˌsʌp ləˈmɛn tə ri /

adjective

1. Also of the nature of or forming a supplement; additional.

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noun

• supplementaries
  plural

1. a person or thing that is supplementary.

supplementary British  

/ ˌsʌplɪˈmɛntərɪ, -trɪ /

adjective

1. Also (less commonly): supplemental.  forming or acting as a supplement

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noun

1. a person or thing that is a supplement

Other Word Forms

Derived Forms

• nonsupplementary
  adjective
• presupplementary
  adjective
• unsupplementary
  adjective
• supplementarily
  adverb

Inflected Forms

Nouns

• supplementaries
  plural

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).

Example Sentences

See Examples For:

supplementary supplementaries

“I’ve been training a little bit more, doing just supplementary things to be able to make sure that I’m in a good place,” Ohtani said after returning to the lineup Monday.

From Los Angeles Times ● Sep. 9, 2026

When we offer supplementary food, such as seeds or meat scraps, this attracts birds of many different species in a combination and number that would not happen in nature.

From Science Daily ● Aug. 24, 2026

Richards said: "They don't need to be fed. A lot of people are thinking: 'It's bone dry out there, everything is brown', but the deer don't need supplementary feeding here at Richmond Park."

From BBC ● Aug. 18, 2026

Not a hard left turn, but a supplementary detail to take with us in the end.

From Salon ● Jun. 15, 2026

Have the students who failed the exam take the supplementary.

From "The Sense of Style" by Steven Pinker

At once a storm of "supplementaries" broke forth.

From Punch, or the London Charivari, Volume 153, July 18, 1917 by Various

A long question to the Board of Trade, on the subject of horse-hides, followed by a series of supplementaries delivered with his customary emphasis, showed that he is not yet resigned to his muzzle.

From Punch, or the London Charivari, Volume 153, August 22, 1917 by Various

The storm of "supplementaries" showed no sign of abating, until the SPEAKER, who rarely fails to find the appropriate phrase, remarked upon "This thirst for information," and so dissolved the House in laughter.

From Punch, or the London Charivari, Volume 153, July 11, 1917 by Various

To-day the lot fell upon Mr. BECK, who good-temperedly explained, when a shower of "supplementaries" rained down upon him, that he really knew nothing about the Department he was temporarily representing.

From Punch, or the London Charivari, Volume 152, March 28, 1917 by Various

Cluster on printed Paper indefinitely extended by supplementaries.

From Punch, or the London Charivari, Vol. 146, April 29, 1914 by Various

Related Words

• ancillary
• auxiliary
• increased