Refractary

Part of speech: adjective, noun

Definitions

1. Stubbornly resistant to authority or discipline; made of material that withstands extreme heat or chemical wear without breaking down
2. Willfully defiant and difficult to manage; composed of substances designed to endure high temperatures and harsh conditions without degradation
3. Defiantly obstinate and hard to govern; possessing the property of resisting melting, corrosion, or damage from intense heat or caustic materials

Etymology: The idea at the root is breaking. Latin "frangere" meant "to break," and "refringere," formed with "re-" to mean "back" or "apart," meant to break up or break open. From its past participle came "refractarius," which English adopted as an adjective for something stubborn or unmanageable, something that cannot be broken to a yoke or bent to discipline. The optical term "refraction," the bending of light, shares this same root. The sense of resisting heat came later. Clay, brick, and lining materials that could endure furnace temperatures without softening or cracking were described as refractory, and the term passed into metallurgy and ceramics. The spelling "refractary" is a less common variant of the same adjective, and "refractory" is the standard form today.