α. Middle English oreison, Middle English oreisoun, Middle English oreisun, Middle English oresone, Middle English oresoun, Middle English oresun, Middle English ureisun, Middle English uresun, Middle English vreisun, Middle English vresone, Middle English vresun, Middle English–1500s oreson, Middle English–1500s oreyson, late Middle English oroysen, 1500s orasoun, 1500s orayson, 1500s–1600s orason, 1500s–1800s oraison, 1600s oraizon; Scottish pre-1700 oraeson, pre-1700 oraison, pre-1700 oraisoun, pre-1700 orasoun, pre-1700 orasoune, pre-1700 oreson, pre-1700 oresone, pre-1700 oresoun, pre-1700 oressoun, pre-1700 vrasoun.
β. Middle English horyson, Middle English orisen, Middle English orisoun, Middle English orisown, Middle English orisson, Middle English orisun, Middle English orisune, Middle English orizoun, Middle English orsones (plural, perhaps transmission error), Middle English orysone, Middle English orysonne, Middle English orysoun, Middle English orysoune, Middle English orysun, Middle English urisun, Middle English vnysoune (transmission error), Middle English vrisun, Middle English vrryson, Middle English vryson, Middle English vrysoun, Middle English (in a late copy)–1600s horison, Middle English–1600s oryson, Middle English– orison, 1500s orisowne, 1500s orizone, 1500s orysion, 1500s urison, 1500s–1600s orision, 1500s–1800s orizon; Scottish pre-1700 orisone, pre-1700 orisoun, pre-1700 orisoune, pre-1700 orysone, pre-1700 orysoun, pre-1700 orysoune, pre-1700 orysown, pre-1700 orysowne, pre-1700 urisone, pre-1700 urisonne, pre-1700 urysown, pre-1700 vriesone, pre-1700 vrison, pre-1700 vrisone, pre-1700 vrisoun, pre-1700 vrysone, pre-1700 wriesone, pre-1700 wrison, pre-1700 wrisoun, pre-1700 wrisoune, pre-1700 wrisown, pre-1700 wrysowne, pre-1700 1700s– orison, 1800s eerisen (Orkney).
N.E.D. (1903) also records a form Middle English urison.