1. Showing or characterized by obstinate resistance to authority or control: refractory children; refractory behavior.
2. Difficult to melt or work; resistant to heat: a refractory material such as silica.
3. Resistant to treatment: a refractory case of acne.
n. pl. re·frac·to·ries
One that is refractory, especially a material that has a high melting point.
[Alteration (influenced by adjectives in -ORY) of obsolete refractary, from Latin refrāctārius, from refrāctus, past participle of refringere, to break up; see REFRACT.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.