Etymology: Middle English dereynen, deraynen, from Old French deraisnier to defend, champion, from de- + raisnier to speak, plead, from (assumed) Vulgar Latin rationare, from Latin ration-, ratio reckoning, calculation, reason — more at reason
archaic : to defend or prove (a claim) or settle (a dispute) especially in personal combat
II. transitive verb
(-ed/-ing/-s)
Etymology: Middle French desrengier to get out of place, disarrange — more at derange
archaic : to discharge from a religious order
Useful english dictionary. 2012.