Hexateuch

n. (Theological term) first 6 books of the Old Testament which include the Torah (Genesis, Exodus, Leviticus, Numbers and Deuteronomy) and the book of Joshua

Hexateuch is a term used by historians and theologians to refer to the first six books of the Bible (the Torah or Pentateuch, and the book of Joshua). In the standard documentary hypothesis, the final edited composition of the books Joshua –  Kings is presumed to be due to the Deuteronomic source tradition, normally dated to the reforms of Josiah. However, beginning with Martin Noth and Julius Wellhausen, some critical scholars have reported traces of the earlier Jahwist and Elohist sources in these books. Both Noth and Wellhausen argued that the books of the Pentateuch should be considered as a unit with the book of Joshua.
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(n.)
The first six books of the Old Testament.
  

[Judaic] The first six books of the Bible. It comprises Genesis, Exodus, Leviticus, Numbers, Deuteronomy and Joshua.