Source : Webster's Revised Unabridged Dictionary (1913)

Processional \Pro*ces"sion*al\, a.
   Of or pertaining to a procession; consisting in a procession.

         The processional services became more frequent.
                                                  --Milman.

Processional \Pro*ces"sion*al\, n. [F. processionnal, LL.
   processionale.]
   1. (R. C. Ch.) A service book relating to ecclesiastical
      processions. --J. Gregory.

   2. A hymn, or other selection, sung during a church
      procession; as, the processional was the 202d hymn.

Source : WordNet®

processional
     adj 1: intended for use in a procession; "processional music";
            "processional cross"
     2: of or relating to or characteristic of a procession; "in
        good processional order"

processional
     n : religious music used in a procession [syn: {prosodion}]