Webster’s Revised Unabridged Dictionary · 1913
Processional
Pro·ces′sion·al (·al), a. Of or pertaining to a procession; consisting in a procession.
The processional services became more frequent. Milman.
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.