What is "octateuch"

Octateuch \Oc"ta*teuch\, n. [L. octateuchus, Gr. ?.] A collection of eight books; especially, the first eight books of the Old Testament. [R.]

n. A collection of eight books; especially, the first eight books of the Old Testament.

The Octateuch is a traditional name for the first eight books of the Bible, comprising the Pentateuch, plus the Book of Joshua, the Book of Judges and the Book of Ruth. These texts make up the first eight books of the Bible in a traditional Christian ordering. This order is quite different from that of the Tanakh where Ruth is considered as part of the third section of the canon (the "Ketubim" or "Writings") and is found after the Song of Solomon, being the second of the Five Megillot.