Etymology

Adjective

1. Obstinate and unruly; strongly opposed to something.
   • 1787, Alexander Hamilton, "Federalist No. 16", December 4,

     in most instances attempts to coerce the refractory and disobedient have been the signals of bloody wars,

   • 1836, Charles Dickens, The Pickwick Papers, Chapter 26,

     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

2. Not affected by great heat.
3. Difficult to treat.
   • 1949, Albert Fields and John Hoesley, "Neck and Shoulder Pain", Calif. Med., 70(6):478–482.,

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

   • 1990, H. A. Ring et al, "Vigabatrin: rational treatment for chronic epilepsy", J. Neurol. Neurosurg.Psychiatry, 53(12):1051–1055,

     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.
   • 1959, Nobusada Ishiko and Werner R. Loewenstein, "Electrical output of a receptor membrane", Science, 1959, 130:1405-6,

     The production of a generator potential leaves a refractory state in the receptor membrane

   • 1970, S.S. Barold et al, "Chest wall stimulation in evaluation of patients with implanted ventricular-inhibited demand pacemakers", Br. Heart J., 32(6):783–789,

     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.