adjuvant

adjective ad·ju·vant \ ˈa-jə-vənt \

|Updated on: 17 Jul 2018

Definition of adjuvant

1 : serving to aid or contribute : auxiliary

2 : enhancing the effectiveness of medical treatment

Retinoids also seem to be useful as adjuvant therapy in the treatment of psoriasis, and they may induce regression of premalignant lesions, including actinic keratoses.
—Robert S. Stern

specifically : of, relating to, or being treatment administered following primary cancer treatment to enhance the outcome of primary treatment

adjuvant chemotherapy following surgery

… women who choose this extensive surgery live no longer than women who choose lumpectomy (with or without adjuvant radiation) and frequent check-ups
—Susan S. Weed

— compare neoadjuvant

adjuvant was our Word of the Day on 09/02/2016. Hear the podcast!

Recent Examples of adjuvant from the Web

These findings led a National Institutes of Health consensus panel to recommend adjuvant chemotherapy for most patients, a practice that has contributed to declining breast cancer mortality.

— sy mukherjee, Fortune, "Tens of Thousands of Early Breast Cancer Patients May Not Need Chemo After All," 4 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'adjuvant.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

Things that are adjuvant rarely get top billing—they're the supporting players, not the stars. But that doesn't mean they're not important. An adjuvant medicine, for example, can have a powerful healing effect when teamed up with another medicine or curative treatment. Adjuvant descends from the Latin verb adjuvare ("to aid"), which also gave English the nouns coadjutor ("assistant") and aid. These days, adjuvant tends to turn up most often in medical contexts, but it can also be used in the general sense of "serving to aid." Likewise, the noun adjuvant can mean "a drug or method that enhances the effectiveness of medical treatment" or simply "one that helps or facilitates."

Origin and Etymology of adjuvant

borrowed from Latin adjuvant-, adjuvans, present participle of adjuvāre "to help, aid, facilitate" — more at ¹aid

NEW! Time Traveler

First Known Use: 1574

in the meaning defined at sense 1

See Words from the same year

adjuvant

noun

Definition of adjuvant

: one that helps or facilitates: such as

a : an ingredient (as in a prescription or a solution) that modifies the action of the principal ingredient

b : something (such as a drug or method) that enhances the effectiveness of medical treatment

used chemotherapy as an adjuvant to surgery

c : a substance (such as one added to a vaccine) enhancing the immune response to an antigen

Recent Examples of adjuvant from the Web

But Ontario, which used a different vaccine with the AS03 adjuvant, did not, according to a study there.

— helen branswell, STAT, "A stubborn medical mystery: Was pandemic flu vaccine tied to an increase in narcolepsy cases?," 5 July 2018
Back in the late 1980s, researchers at the Max Planck Institute of Psychiatry injected the right hind paw of a rat with Freund’s complete adjuvant, a compound that triggers inflammation, as part of a test of chronic pain treatments.

— jonathon keats, Discover Magazine, "Building a Better Painkiller," 11 May 2018
Stein, who is now chair of the anesthesiology department at the Charité hospital and Free University of Berlin, has tested NFEPP on rats inflamed with Freund’s complete adjuvant, and the initial results are encouraging.

— jonathon keats, Discover Magazine, "Building a Better Painkiller," 11 May 2018
What makes Shingrix so much better is the inclusion of a substance called an adjuvant that boosts the body’s immune response to the vaccine.

— jane e. brody, New York Times, "Why You Should Get the New Shingles Vaccine," 9 Apr. 2018
The study claimed that aluminum adjuvants in the human papillomavirus (HPV) vaccine Gardasil caused behavioral changes in mice.

— beth mole, Ars Technica, "Study claims vaccines-autism link; scientists find fake data, have rage stroke," 11 Oct. 2017
This vaccine uses a new adjuvant [an immune-system booster].

— Washington Post, "What you need to know about the new shingles vaccine," 28 Oct. 2017
Most adjuvants are not compatible with the microneedle patch, Prausnitz says.

— emily matchar, Smithsonian, "Needle-Free Patch Makes Vaccination as Easy as Putting on a Band-Aid," 17 July 2017
Scientists attribute its stunning effectiveness to a new adjuvant, an additional chemical in the vaccine that primes the immune system for the viral protein.

— sarah zhang, The Atlantic, "Why Do We Need Separate Chicken-Pox and Shingles Vaccines?," 25 Oct. 2017