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re·​frac·​to·​ry ri-ˈfrak-t(ə-)rē How to pronounce refractory (audio)
: resisting control or authority : stubborn, unmanageable
: resistant to treatment or cure
a refractory lesion
: unresponsive to stimulus
: immune, insusceptible
after recovery they were refractory to infection
: difficult to fuse, corrode, or draw out
especially : capable of enduring high temperature
ri-ˈfrak-t(ə-)rə-lē How to pronounce refractory (audio)
refractoriness noun


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plural refractories
: a refractory person or thing
especially : a heat-resisting ceramic material

Did you know?

Refractory is from the Latin word refractarius. During the 17th century, it was sometimes spelled as refractary, but that spelling, though more in keeping with its Latin parent, had fallen out of use by the century's end. Refractarius, like refractory, is the result of a slight variation in spelling. It stems from the Latin verb refragari, meaning "to oppose."

Choose the Right Synonym for refractory

unruly, ungovernable, intractable, refractory, recalcitrant, willful, headstrong mean not submissive to government or control.

unruly implies lack of discipline or incapacity for discipline and often connotes waywardness or turbulence of behavior.

unruly children

ungovernable implies either an escape from control or guidance or a state of being unsubdued and incapable of controlling oneself or being controlled by others.

ungovernable rage

intractable suggests stubborn resistance to guidance or control.

intractable opponents of the hazardous-waste dump

refractory stresses resistance to attempts to manage or to mold.

special schools for refractory children

recalcitrant suggests determined resistance to or defiance of authority.

acts of sabotage by a recalcitrant populace

willful implies an obstinate determination to have one's own way.

a willful disregard for the rights of others

headstrong suggests self-will impatient of restraint, advice, or suggestion.

a headstrong young cavalry officer

Examples of refractory in a Sentence

Adjective refractory players will be ejected from the game believing that rules are only for other people, he's been refractory virtually his entire life
Recent Examples on the Web
This current study extends the successful results previously published on the virus-free preparation of CD19-specific CAR T-cells against refractory B cell malignancies utilizing Applied DNA's Linea™ DNA. Kansas City Star, 13 May 2024 Marinus Pharmaceuticals said an experimental treatment for refractory status epilepticus failed to meet early stopping criteria for a Phase 3 study. Meghana Keshavan, STAT, 15 Apr. 2024 All of the children had rare, relapsed or refractory cancers and were running out of treatment options. Michelle Marchante, Miami Herald, 11 Apr. 2024 Many of those patients were able to receive a potentially curative stem cell transplant later on, which is often the ultimate goal for patients with relapsed or refractory patients. Damian Garde, STAT, 13 Dec. 2023 Of these, the company said 10 million suffer from refractory chronic cough, 6 million of whom are based in the EU and the U.S., where there is no approved treatment. Robert Hart, Forbes, 18 Apr. 2023 About 28 million patients worldwide suffer from refractory chronic cough, which the cough medicine camlipixant targets., 18 Apr. 2023 With the acquisition, GSK will get the experimental drug camlipixant, which is in a Phase 3 trial for refractory chronic cough. Ed Silverman, STAT, 18 Apr. 2023 Made with refractory material like that found in faux fireplace logs, the spooky stoneware skulls are fireproof and lightweight. Kirby Adams, The Courier-Journal, 12 Oct. 2021
The drugs treat an autoimmune disease, thyroid eye disease, and an inflammatory condition, chronic refractory gout. Rebecca Robbins,, 16 May 2023 Dolastatin 10-based ADCs have been approved for treatment of different lymphomas and refractory bladder cancer. Brittany Edelmann, Discover Magazine, 14 Oct. 2022 Our systematic approach to research enabled the first-ever treatment (siltuximab) and discovery of a treatment for patients who are siltuximab-refractory, like me. K.n.c., The Economist, 27 Nov. 2019 Almost a third endure refractory epilepsy, meaning typical pharmaceutical drugs have little effect in reducing the instances or frequency of seizures. Robert Iddiols, CNN, 28 Sep. 2019

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'refractory.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History



alteration of refractary, from Latin refractarius, irregular from refragari to oppose, from re- + -fragari (as in suffragari to support with one's vote)

First Known Use


1606, in the meaning defined at sense 1


1627, in the meaning defined above

Time Traveler
The first known use of refractory was in 1606


Dictionary Entries Near refractory

Cite this Entry

“Refractory.” Dictionary, Merriam-Webster, Accessed 25 Jun. 2024.

Kids Definition


: resisting control or authority : stubborn
a refractory child
: resistant to treatment : unresponsive
: capable of enduring high temperatures

Medical Definition


re·​frac·​to·​ry ri-ˈfrak-t(ə-)rē How to pronounce refractory (audio)
: resistant to treatment or cure
a refractory fulminant lesion
had disease that was extremely refractory to multiple intensive therapiesMichelle L. Bennett et al.
: unresponsive to stimulus
the refractory period of a muscle fiber
: resistant or not responding to an infectious agent : immune
refractory to reinfection

More from Merriam-Webster on refractory

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