Black's Law Dictionary (2nd edition)dictionaries

Gountermand

A change or revoca-tlon of orders, authority, or instructions pre-vlously issued. It may be either express or implied ; the former where the order or instruction already given is explicitly annulled or recalled; the latter where the party’s con-duct is lncompatible with the further con-tinuance of the order or instruction, as where a new order is given Inconsistent with the former order

Source: Black’s Law Dictionary 2nd Ed (1910)