English Language Learners Definition of counterespionage. formal : the activity of preventing or stopping enemies from spying. See the full definition for counterespionage in the English Language Learners Dictionary.

counterespionage. That aspect of counterintelligence designed to detect, destroy, neutralize, exploit, or prevent espionage activities through identification, penetration, manipulation, deception, and repression of individuals, groups, or organizations conducting or suspected of conducting espionage activities.

Counterespionage, espionage directed toward detecting and thwarting enemy espionage. See intelligence (in government operations).