Ecclesiasticus, book written in Hebrew by a Jew living in Egypt, and translated into Greek by his grandson Jesus ben Sirach. It was called Ecclesiasticus because it was frequently read in churches, and was thus called
liber ecclesiasticus (Latin for 'church book'). Today it is more frequently known as Sirach.
Ecclesiasticus is accepted as part of the The Canon of Scripture by Catholics and Eastern Orthodox, but not by Protestants.