Contains
- infiltrator
Someone who takes up a position surreptitiously for the purpose of espionage.
- sleeper
A spy or saboteur or terrorist planted in an enemy country who lives there as a law-abiding...
- foreign agent
A spy for a foreign country.
- espionage agent
Someone employed to spy on another country or business competitor.
- double agent
A spy who works for two mutually antagonistic countries.
- mole
A spy who works against enemy espionage.