Counterespionage (noun)

1. The act or practice of identifying and preventing espionage by an enemy or rival.
2. Activities taken by a government or organization to prevent the gathering of classified or confidential information by foreign agents or organizations.

Origin:

Derived from the prefix "counter" meaning opposing or opposite, and the word "espionage" meaning the practice of spying or secret gathering of information.

Examples:

1. The counterespionage unit of the FBI is responsible for detecting and preventing foreign intelligence operations within the United States.
2. The company's counterespionage efforts have been successful in preventing competitors from obtaining sensitive information.
3. Counterespionage refers to actions taken to prevent espionage by an enemy or rival.
4. The counterespionage operation was a success and the spy ring was broken up.
5. Counterespionage activities are critical for maintaining national security and protecting sensitive information.