The Collaborative International Dictionary of English v.0.48:
Cautery \Cau"ter*y\, n.; pl. Cauteries. [L. cauterium, Gr. ?.
1. (Med.) A burning or searing, as of morbid flesh, with a
hot iron, or by application of a caustic that will burn,
corrode, or destroy animal tissue.
2. The iron of other agent in cauterizing.
Actual cautery, a substance or agent (as a hot iron) which
cauterizes or sears by actual heat; or the burning so
Potential cautery, a substance which cauterizes by chemical
action; as, lunar caustic; also, the cauterizing produced
by such substance.