counterspy

noun 0.749

counterintelligence

noun 0.746

countersurveillance

noun 0.701

industrial espionage

noun 0.627

spy ring

noun 0.623

spycraft

noun 0.621

countersubversive

noun 0.597

counterterror

noun 0.590

anticounterfeiting

noun 0.585

counterinsurgency

noun 0.574

counterterrorist

noun 0.542

covertness

noun 0.540

secret agent

noun 0.538

countermeasure

noun 0.531

covert

noun 0.530

spy

noun 0.524

exfiltration

noun 0.517

spymaster

noun 0.510

cryptography

noun 0.504

double agent

noun 0.504