Espionage Definition: The practice of playing the spy, or of employing spies. Related Terms: Spy / Spies In Qu v Canada, Justice Lemieux of the Federal Court of Canada adopted these words:"[E]spionage means the practice of playing the spy, or of employing spies...."The act of spying. The occupation of spies ... a secret organization existing in all nations and of which the function is to reveal the secrets of foreign or enemy powers."Espionage is a method of information gathering."There are basically three major categories of covert sources of intelligence: aerial and space reconnaissance (Military Reconnaissance), electronic eavesdropping and the secret agent."REFERENCES:Qu v Canada, [2000] 4 FC 72Re Wenberg, 4 IAC 292 Categories & Topics: Immigration Law Dictionary International Law Dictionary Military Law Dictionary Find you are constantly looking up definitions? Try our search provider (works in most modern browsers) If you find an error or omission in Duhaime's Legal Dictionary, or if you have legal term suggestion, we'd love to hear from you!