countermand (v.)

"to revoke (a command or order)," early 15c., contremaunden, from Anglo-French and Old French contremander "reverse an order or command" (13c.), from contre- "against" (see contra (prep., adv.)) + mander, from Latin mandare "to order" (see mandate (n.)). Related: Countermanded; countermanding. As a noun, "a contrary order," 1540s.