Refractory

Obstinate in disobedience; contumacious; stubborn; unmanageable; as, a refractory child; a refractory beast.

Resisting ordinary treatment; difficult of fusion, reduction, or the like; -- said especially of metals and the like, which do not readily yield to heat, or to the hammer; as, a refractory ore.

A refractory person.

Refractoriness.

OPottery) A piece of ware covered with a vaporable flux and placed in a kiln, to communicate a glaze to the other articles.