Countermand (verb)

1. To revoke or cancel an order or command.
2. To issue an order that contradicts or overrules a previous order.

Origin:

Derived from the latin word "contramandare" meaning "to give opposite orders".

Examples:

1. The manager countermanded the previous order to close the store early.
2. The company countermanded the previous decision to outsource the project.
3. The general countermanded the previous order to retreat, and ordered the troops to advance.
4. The president countermanded the previous executive order, reversing it.
5. The teacher countermanded the previous instructions and gave new ones to the students.