The Collaborative International Dictionary of English v.0.48:

Ecclesiasticus \Ec*cle`si*as"ti*cus\, n. [L.]
   A book of the Apocrypha.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Ecclesiasticus
    n 1: an Apocryphal book mainly of maxims (resembling Proverbs in
         that respect) [syn: Ben Sira, Sirach, Ecclesiasticus,
         Wisdom of Jesus the Son of Sirach]