Easton's Bible Dictionary
The holy writings, a term which came early into use in the Christian church to denote the third division of the Old Testament scriptures, called by the Jews Kethubim, i.e., "Writings." It consisted of five books, viz., Job, Proverbs, and Psalms, and the two books of Chronicles. The ancient Jews classified their sacred books as the Law, the Prophets, and the Kethubim, or Writings. (see BIBLE.)
In the New Testament (Luke 24:44) we find three corresponding divisions, viz., the Law, the Prophets, and the Psalms.
Noah Webster's New International Dictionary of the English Language
1. (n. pl.) The last of the three Jewish divisions of the Old Testament, or that portion not contained in the Law and the Prophets. It comprises Psalms, Proverbs, Job, Canticles, Ruth, Lamentations, Ecclesiastes, Esther, Daniel, Ezra, Nehemiah, and Chronicles.
2. (n. pl.) The lives of the saints.