What is Adipocere?

Legal Definition
Adipocere (/ˈædpəˌsɪər, -p-/), also known as corpse, grave or mortuary wax, is a wax-like organic substance formed by the anaerobic bacterial hydrolysis of fat in tissue, such as body fat in corpses. In its formation, putrefaction is replaced by a permanent firm cast of fatty tissues, internal organs, and the face.
-- Wikipedia
Legal Definition
A waxy substance (chemically margarate of ammonium or ammonia-cal soap) formed by the decomposition of animal matter protected from the air but subjected to moisture; in medical jurisprudence, the substance into which a human cadaver is converted which has been buried for a long time in a saturated soil or has lain long in water.
-- Black's Law Dictionary