It's from the Late Latin, Deuteronomium, from Greek Deuteronomion, literally "second law," from deuteros "second" + nomos "law" (see numismatics). A mistranslation of Hebrew mishneh hattorah hazzoth "a copy of this law" [Deut. xvii:18]. The book is a repetition, with comments, of the Decalogue and most of the laws of Exodus. The title was translated literally into Old English as æfteræ, literally "after-law."