The word for today is…
countermand (verb) – 1. To cancel or reverse (a previously issued command or order).
2. To recall by a contrary order.
(noun) – 1. An order or command reversing another one.
2. Cancellation of an order or command.
Source : The Free Dictionary
Etymology : In the military, one’s mandate is to follow the commands (and sometimes the countermands) of the officers. Doing their bidding is not particularly commendable—it’s simply mandatory. The Latin verb mandare, meaning “to entrust” or “to order,” is the authority behind countermand. It’s also behind the words mandate, command, demand, commend (which can mean “to entrust” as well as “to praise”), and mandatory. Countermand came to English via Anglo French, where the prefix cuntre- (“against”) was combined with the verb mander (“to command”). It has been a part of our language since the 1400s.