refractory

adj

1. Obstinate and unruly; strongly opposed to something.

   “[…] in most instances attempts to coerce the refractory and disobedient have been the signals of bloody wars, […]”

   “Mr. Weller knocked at the door, and after a pretty long interval—occupied by the party without, in whistling a tune, and by the party within, in persuading a refractory flat candle to allow itself to be lighted […]”

   “For five minutes Pollyanna worked swiftly, deftly, combing a refractory curl into fluffiness, perking up a drooping ruffle at the neck, or shaking a pillow into plumpness so that the head might have a better pose. Meanwhile the sick woman, frowning prodigiously, and openly scoffing at the whole procedure, was, in spite of herself, beginning to tingle with a feeling perilously near to excitement.”

   “And the camels galled, sore-footed, refractory, Lying down in the melting snow.”

2. Not affected by great heat.

   “Pure lime is extremely refractory, but readily fusible if any silex is brought in contact with it; […]”

   “There are also over 1,200 pallet brick wagons used for the conveyance of refractory bricks.”

3. Resistant to treatment; not responding adequately to therapy.

   “Many of the vague and refractory cases of neck and shoulder pain and of migraine may be due to cervical disc disease.”

   “In 33 adult patients with long standing refractory epilepsy on treatment with one or two standard anti-convulsant drugs,”

4. Incapable of registering a reaction or stimulus.

   “The production of a generator potential leaves a refractory state in the receptor membrane […]”

   “The […] delivery of external stimuli […] delineates the pacemaker refractory period after the emission of a pacing stimulus and after the sensing of a spontaneous beat.”

noun

1. A material or piece of material, such as a brick, that has a very high melting point.
2. A plant or factory that produces such material.