Meaning

noun lining consisting of material with a high melting point; used to line the inside walls of a furnace

adjective not responding to treatment

adjective temporarily unresponsive or not fully responsive to nervous or sexual stimuli

originFrom Latin refractārius (“obstinate”), from refrāctus, past participle of refringere (“to break up”). Originally refractary, refractarie, but reanalysed after other adjectives in -ory.

Etymology from Wiktionary, CC BY-SA 3.0