Source : Webster's Revised Unabridged Dictionary (1913)

Archdeacon \Arch`dea"con\, n. [AS. arcediacon, archidiacon, L.
   archidiaconus, fr. Gr. ?. See {Arch-}, pref., and {Deacon}.]
   In England, an ecclesiastical dignitary, next in rank below a
   bishop, whom he assists, and by whom he is appointed, though
   with independent authority. --Blackstone.

Source : WordNet®

archdeacon
     n : (Anglican Church) an ecclesiastical dignitary usually
         ranking just below a bishop