Word Origin & History
1410, "dodging movements of a hunted animal," from O.Fr. ruse (14c.), noun use of ruser "to dodge, repel, retreat," from L. recusare "deny, reject, oppose," from re- intensive prefix, + causari "plead as a reason, object, allege," from causa "reason, cause." Or the O.Fr. word may be from L. rursus "backwards."
"A French word neither elegant nor necessary." [Johnson] But the verb ruse was used in M.E.