espionage

noun

es·​pi·​o·​nage ˈe-spē-ə-ˌnäzh  -ˌnäj 

-nij,

 Canadian also  -ˌnazh;

ˌe-spē-ə-ˈnäzh;

i-ˈspē-ə-nij

: the practice of spying or using spies to obtain information about the plans and activities especially of a foreign government or a competing company

industrial espionage

Synonyms

• spying

Examples of espionage in a Sentence

He was charged with several counts of espionage.

the acts of espionage on behalf of the Confederacy carried on by Belle Boyd and Rose Greenhow

Recent Examples on the Web

In prepared remarks for a hearing on Wednesday, Warner says nearly 25% of agents who typically handle counterterrorism, cybercrime, and espionage have been reassigned to immigration enforcement. —Amanda Castro, MSNBC Newsweek, 8 Oct. 2025

With a single-player campaign set in the Nineties, the game’s story had a deliriously fun espionage hook that harkened back to the series’ heyday of the original Modern Warfare trilogy and early Black Ops titles. —Christopher Cruz, Rolling Stone, 7 Oct. 2025

Those actions have caused unprecedented turmoil at the Eastern District, which oversees some of the nation's most sensitive national security, terrorism and espionage investigations. —Alexander Mallin, ABC News, 6 Oct. 2025

In March, Google addressed CVE-2025-2783, a sandbox escape bug exploited in espionage attacks against Russian organizations. —Kurt Knutsson, FOXNews.com, 2 Oct. 2025

Word History

Etymology

French espionnage, from Middle French, from espionner to spy, from espion spy, from Old Italian spione, from spia, of Germanic origin; akin to Old High German spehōn to spy — more at spy

First Known Use

1793, in the meaning defined above

Kids Definition

espionage

noun

es·​pi·​o·​nage ˈes-pē-ə-ˌnäzh  -näj 

-ˌnij

: the practice of spying : the use of spies

Legal Definition

espionage

noun

es·​pi·​o·​nage ˈes-pē-ə-ˌnäzh, -ˌnäj, -nij 

: the practice of gathering, transmitting, or losing through gross negligence information relating to the defense of the U.S. with the intent that or with reason to believe that the information will be used to the injury of the U.S. or the advantage of a foreign nation