Sleeper and Spy

Sleeper noun - A spy or saboteur or terrorist planted in an enemy country who lives there as a law-abiding citizen until activated by a prearranged signal.

Spy and sleeper are semantically related. In some cases you can use "Spy" instead a noun "Sleeper".

Nearby Words: sleep, sleepy, sleeping

Spy noun - A person who tries secretly to obtain information for one country in the territory of another usually unfriendly country.

Sleeper and spy are semantically related. Sometimes you can use "Sleeper" instead a noun "Spy".

Nearby Word: spying