ruse (n.)

early 15c., "dodging movements of a hunted animal;" 1620s, "a trick," from Old French ruse, reuse "diversion, switch in flight; trick, jest" (14c.), back-formed noun from reuser "to dodge, repel, retreat; deceive, cheat," from Latin recusare "deny, reject, oppose," from re-, intensive prefix (see re-), + causari "plead as a reason, object, allege," from causa "reason, cause" (see cause (n.)). It also has been proposed that the French word may be from Latin rursus "backwards," or a Vulgar Latin form of refusare. Johnson calls it, "A French word neither elegant nor necessary." The verb ruse was used in Middle English.