Spying is a tense and often deadly way for governments to gather secret information from their enemies. Learn how spies are recruited and how they obtain information. 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.

How to use spy in a sentence. 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. Phrasal verb spy on someone/something (definition of spying from the cambridge advanced learner's dictionary & thesaurus Β© cambridge university press)