Entry 3 senses · 2 variants Webster, 1913 Processional /prəs-ĕsh'-ən-əl/ · Pro·ces·sion·al · IPA /prəsˈɛʃənəl/ a. n. 01 a. Of or pertaining to a procession; consisting in a procession. 1. Of or pertaining to a procession; consisting in a procession. “The processional services became more frequent.” — Milman. 02 n. A service book relating to ecclesiastical processions. 1. A service book relating to ecclesiastical processions.(R. C. Ch.) 2. A hymn, or other selection, sung during a church procession; as, the processional was the 202d hymn.