intractable not tractable; difficult to manage or mold; "an intractable disposition"; "intractable pain"; "the most intractable issue of our era"; "intractable metal"
medical specialty,
medicine the learned profession that is mastered by graduate training in a medical school and that is devoted to preventing or alleviating or curing diseases and injuries; "he studied medicine at Harvard"
refractory -
temporarily unresponsive or not fully responsive to nervous or sexual stimuli; "the refractory period of a muscle fiber"
refractory -
stubbornly resistant to authority or control; "a fractious animal that would not submit to the harness"; "a refractory child"
A refractory material is one that retains its strength at high temperatures. ASTM C71 defines refractories as "non-metallic materials having those chemical and physical properties that make them applicable for structures, or as components of systems, that are exposed to environments above 1,000 °F (811 K; 538 °C)". Refractory materials are used in linings for furnaces, kilns, incinerators and reactors.
