1. A book in the Bible that repeats the Ten Commandments and records much of the Mosaic Law. It is the fifth book of the Pentateuch.
2. Etymology: from Greek Deuteronomion; literally, "second law", from deuteros, "second" + nomos, "law". From the 14th century via late Latin from Greek Deuteronomion, "second law"; because the book contains a repetition of the Decalogue and parts of Exodus.