spy

Examples:: Margarete Gertrud Zelle
Dutch dancer who was executed by the French as a German spy in World War I (1876-1917)

Types:: show 6 types...; hide 6 types...; counterspy, mole
a spy who works against enemy espionage; double agent
a spy who works for two mutually antagonistic countries; espionage agent
someone employed to spy on another country or business competitor; foreign agent
a spy for a foreign country; 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 citizen until activated by a prearranged signal

Type of:: intelligence agent, intelligence officer, operative, secret agent
a person secretly employed in espionage for a government

“my spies tell me that you had a good time last night”

Types:: snoop, snooper
a spy who makes uninvited inquiries into the private affairs of others; shadow, shadower, tail
a spy employed to follow someone and report their movements; eavesdropper
a secret listener to private conversations

Type of:: looker, spectator, viewer, watcher, witness
a close observer; someone who looks at something (such as an exhibition of some kind)

Type of:: monitor, supervise
keep tabs on; keep an eye on; keep under surveillance

Types:: show 7 types...; hide 7 types...; descry, espy, spot
catch sight of; detect, discover, find, notice, observe
discover or determine the existence, presence, or fact of; catch out, find out
trap; especially in an error or in a reprehensible act; sense
detect some circumstance or entity automatically; instantiate
find an instance of (a word or particular usage of a word); trace
discover traces of; see
observe as if with an eye

“spy for the Russians”

Type of:: enquire, inquire, investigate
conduct an inquiry or investigation of

DEFINITIONS OF: spy