The Collaborative International Dictionary of English v.0.48:

Ecclesiastical \Ec*cle`si*as"tic*al\, a. [See Ecclesiastical,
   a.]
   Of or pertaining to the church; relating to the organization
   or government of the church; not secular; as, ecclesiastical
   affairs or history; ecclesiastical courts.
   [1913 Webster]

         Every circumstance of ecclesiastical order and
         discipline was an abomination.           --Cowper.
   [1913 Webster]

   Ecclesiastical commissioners for England, a permanent
      commission established by Parliament in 1836, to consider
      and report upon the affairs of the Established Church.

   Ecclesiastical courts, courts for maintaining the
      discipline of the Established Church; -- called also
      Christian courts. [Eng.]

   Ecclesiastical law, a combination of civil and canon law as
      administered in ecclesiastical courts. [Eng.]

   Ecclesiastical modes (Mus.), the church modes, or the
      scales anciently used.

   Ecclesiastical States, the territory formerly subject to
      the Pope of Rome as its temporal ruler; -- called also
      States of the Church.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ecclesiastical
    adj 1: of or associated with a church (especially a Christian
           Church); "ecclesiastic history" [syn: ecclesiastical,
           ecclesiastic]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "ecclesiastical":
   abbatial, abbatical, apostolic, archiepiscopal, canonical,
   capitular, capitulary, cathedral-like, cathedralesque, church,
   churchish, churchlike, churchly, clerical, ecclesiastic, episcopal,
   episcopalian, evangelistic, ministerial, pantheonic, papal,
   pastoral, patriarchal, pontifical, prelatial, prelatic,
   priest-ridden, priestish, priestly, rabbinic, sacerdotal,
   spiritual, synagogal, synagogical, tabernacular, templelike,
   theological, ultramontane



Bouvier's Law Dictionary, Revised 6th Ed (1856):

ECCLESIASTICAL. Belonging to, or set apart for the church; as, distinguished
from civil or secular. Vide Church.