orison n. + Add to list ori·son SynonymsEtymology Synonyms petitionprayerOriginLATōrātiō→OFRoraisun→XNOoreison→MEorisoun→ENorison From Middle English orisoun, from Anglo-Norman oreison, oresoun etc. and Old French oraisun etc., from Latin ōrātiō, ōrātiōnem (“discourse, prayer”) (whence also English oration).