supplemental

American  

[suhp-luh-men-tl] / ˌsʌp ləˈmɛn tl /

adjective

1. supplementary.

2. nonscheduled.

3. (of a pleading, an affidavit, etc.) added to furnish what is lacking or missing.

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noun

1. anything that is supplemental.

   supplementals attached to the bill in committee.

Other Word Forms

• nonsupplemental
  adjective
• nonsupplementally
  adverb
• presupplemental
  adjective
• supplementally
  adverb
• unsupplemental
  adjective

Etymology

Origin of supplemental

First recorded in 1595–1605; supplement + -al ¹

Explanation

You can use the adjective supplemental to describe something extra. You could volunteer to donate your collection of markers and colored pencils to a local school that needs supplemental art supplies. Something that's supplemental is added when there's a lack or deficiency. You might feed the runt from a litter of puppies supplemental milk because he can't get enough from his mother. Teachers are famous for assigning supplemental reading to round out the information in a textbook. Supplemental comes from the Latin supplementum, "added to supply a deficiency."

Example Sentences

Most climbers rely on supplemental oxygen at this altitude, and even then mountaineering experts advise against staying in the zone for more than 20 hours.

From BBC • May 22, 2026

“Harry Potter and the Sorcerer’s Stone” is the latest film to be given the Cosm treatment, in which supplemental animations seek to envelop guests.

From Los Angeles Times • May 19, 2026

For people who plan to use their benefits for residential care, supplemental private insurance will be key.

From MarketWatch • May 13, 2026

What once functioned as supplemental classroom software has effectively become critical educational infrastructure.

From Salon • May 9, 2026

Namba had perished on the South Col, just twenty minutes from shelter, assigned to a summit party, and on May 16 he reached the top without supplemental oxygen.

From "Into Thin Air" by Jon Krakauer