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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

Example Sentences

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
An effect size of 1.58 was reported for refractory hallucinations, which is remarkably large when compared with the effect sizes of antipsychotic medication (0.4–0.6). Neuroskeptic, Discover Magazine, 13 Nov. 2012 In October, the FDA approved a second CAR-T therapy, axicabtagene ciloleucel (developed by Kite Pharma and dubbed Yescarta), for patients with relapsed or refractory non-Hodgkin lymphoma. Kenneth Miller, Discover Magazine, 29 Dec. 2017 Interim results from two Phase 3 studies show the ability of ibrexafungerp to combat refractory fungal infections in a hospital setting. Joshua Cohen, Forbes, 6 July 2022 However, there is some concern regarding the safety of PPI treatment, as well as the fact that a subset of patients are refractory. Joshua Cohen, Forbes, 1 June 2022 At an outpatient clinic, Tawfik treats rare and refractory types of pain usually associated with surgery or injury, such as chronic neuropathic pain and complex regional pain syndrome. Troy Farah, Scientific American, 30 Sep. 2021 There have been some positive developments for Bristol Myers Squibb as well, including the EU approval for Abecma - the First Anti-BCMA CAR T Cell Therapy - for relapsed and refractory multiple myeloma. Trefis Team, Forbes, 28 Sep. 2021 Many less attractive traits are also recorded: Charles could be uncommunicative and dilatory, evasive and mendacious, refractory, vindictive, obstinate, even outright wicked, though self-delusive about the motives of others. R.j.w. Evans, The New York Review of Books, 11 June 2020 Cinematographer Yves Bélanger was having a fair amount of fun with fish-eye lenses, refractory visual effects, and askew angles. Roxana Hadadi, Vulture, 15 Sep. 2021
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 See More

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

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 9 Feb. 2023.

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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