The Collaborative International Dictionary of English v.0.48:
Archidiaconal \Ar`chi*di*ac"o*nal\, a. [L. archidiaconus, Gr. ?, equiv. to E. archdeacon.] Of or pertaining to an archdeacon. [1913 Webster] This offense is liable to be censured in an archidiaconal visitation. --Johnson. [1913 Webster]WordNet (r) 3.0 (2006):
archidiaconal adj 1: of or relating to an archdeacon or his office