What is "pinacone"

Pinacone \Pin"a*cone\, n. [From Gr. ?, ?, a tablet. So called because it unites with water so as to form tablet-shaped crystals.] (Chem.) A white crystalline substance related to the glycols, and made from acetone; hence, by extension, any one of a series of substances of which pinacone proper is the type. [Written also pinakone.]

n. 1 (context organic compound English) A white crystalline substance related to the glycols, and made from acetone. 2 (context organic compound by extension English) Any of a series of substances of which pinacone proper is the type.