Source : Webster's Revised Unabridged Dictionary (1913)

Recessional \Re*ces"sion*al\, a.
   Of or pertaining to recession or withdrawal.

   {Recessional hymn}, a hymn sung in a procession returning
      from the choir to the robing room.

Source : WordNet®

recessional
     adj : of or relating to receding

recessional
     n 1: the withdrawal of the clergy and choir from the chancel to
          the vestry at the end of a church service [syn: {recession}]
     2: a hymn that is sung at the end of a service as the clergy
        and choir withdraw