orison (n.)

c. 1200, orisoun, "a prayer," especially "a set prayer that forms part of a religious service," from Anglo-French oreison, Old French oreisun (12c., Modern French oraison) "oration," from Latin orationem (nominative oratio) "speech, oration," in Church Latin "prayer, appeal to God," noun of action from past-participle stem of ōrare "to speak, pray, plead" (see orator). Etymologically, a doublet of oration.