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  

/ -trɪ, ˌsʌplɪˈmɛntərɪ /

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

Meanwhile, fiscal expansion efforts in Japan such as public-private investment and supplementary budgets are poised to build simultaneously, two analysts of JPMorgan’s Global Markets Strategy say in a research report.

From The Wall Street Journal ● Jun. 29, 2026

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

From Salon ● Jun. 15, 2026

A supplementary budget is usually published by the Welsh government in the summer to reflect any changes to its financial position mid-way through a financial year.

From BBC ● Jun. 14, 2026

The company’s supplementary tax payment accounts for around 28% of Nomura’s estimated net profit attributable to shareholders for fiscal year 2026, they point out.

From The Wall Street Journal ● Jun. 4, 2026

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

There were other garments and supplementaries, all treated in the same way.

From A Woman-Hater by Reade, Charles

Cluster on printed Paper indefinitely extended by supplementaries.

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

At once a storm of "supplementaries" broke forth.

From Punch, or the London Charivari, Volume 153, July 18, 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

Related Words

• ancillary
• auxiliary
• increased