Source : Webster's Revised Unabridged Dictionary (1913)

Subdeacon \Sub*dea"con\, n. [Pref. sub- + deacon: cf. L.
   subdiaconus.] (Eccl.)
   One belonging to an order in the Roman Catholic Church, next
   interior to the order of deacons; also, a member of a minor
   order in the Greek Church.

Source : WordNet®

subdeacon
     n : a clergyman an order below deacon; one of the Holy Orders in
         the unreformed western Christian Church and the eastern
         Catholic Churches but now suppressed in the Roman
         Catholic Church