Espionage, spying, or intelligence gathering, as a subfield of the intelligence field, is the act of obtaining secret, confidential, or in some way valuable information.

Phrasal verb spy on someone/something (Definition of spying from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

Espionage is defined as the act of spying or using spies, agents, assets, and intelligence officers, as well as technology, to collect secret information, usually through illegal means.

1. To engage in espionage. 2. To investigate or observe something, especially in secret: spying into the neighbor's activities.

Spies might seem like a throwback to earlier days of world wars and cold wars, but they are more common than ever—and they are targeting our nation’s most valuable secrets. The FBI is the lead...

The meaning of SPY is to watch secretly usually for hostile purposes. How to use spy in a sentence.

Dec 10, 2025 · From face scans, phones, and fingerprints to bulk data collection, here's how modern surveillance is reshaping (and watching) your life.

/ˈspaɪɪŋ/ IPA guide Other forms: spyings Definitions of spying noun keeping a secret or furtive watch see more

Nov 7, 2025 · Following the surrender of Nazi Germany in May 1945 near the close of World War II, the uneasy wartime alliance between the United States and Great Britain on the one hand and the Soviet …

Jun 16, 2025 · Discover 25 intriguing facts about the concept and history of spying, from ancient espionage tactics to modern intelligence operations.