4 synonym groups for Spion

eye, eyeball, optic, oculus, peeper [x]

espionage, surveillance, snooping, eavesdropping, reconnaissance, intelligence gathering, infiltration, shadowing, tailing, monitoring, observation, undercover work, secret service, covert operations, stakeout, wiretapping, bugging, surveillance operations, clandestine activities, secret watching, intelligence operations, secret observation, secret monitoring, secret surveillance, secret reconnaissance, secret intelligence, secret infiltration, secret shadowing, secret tailing, secret undercover work, secret service activities, covert surveillance, covert intelligence, covert reconnaissance, covert infiltration, covert shadowing, covert tailing, covert monitoring, covert observation, covert undercover work, clandestine surveillance, clandestine intelligence, clandestine reconnaissance, clandestine infiltration, clandestine shadowing, clandestine tailing, clandestine monitoring, clandestine observation [x]

espionage, surveillance, reconnaissance, intelligence-gathering, snooping, eavesdropping, infiltration, covert operation, undercover work, secret mission, stakeout, shadowing, tailing, bugging, wiretapping, monitoring, observation, tracking, following, clandestine activity, secret surveillance, intelligence operation, secret observation, secret monitoring, secret tracking, secret following, secret reconnaissance, secret intelligence-gathering, secret snooping, secret eavesdropping, secret infiltration, covert surveillance, covert monitoring, covert tracking, covert following, covert reconnaissance, covert intelligence-gathering, covert snooping, covert eavesdropping, covert infiltration, undercover surveillance, undercover monitoring, undercover tracking, undercover following, undercover reconnaissance, undercover intelligence-gathering, undercover snooping, undercover eavesdropping, undercover infiltration [x]

eavesdropping, bugging, surveillance, interception, tapping, monitoring, spying, snooping [x]