{ } n. (Min.) A mineral of a steel-gray or iron-black color; tin pyrites. It is a sulphide of tin, copper, and iron. [ 1913 Webster ]
n. [ Cf. F. tannin. ] (Chem.) Same as Tannic acid, under Tannic. [ 1913 Webster ]
n. The art or process of converting skins into leather. See Tan, v. t., 1. [ 1913 Webster ]