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

The intention after writing Slow Horses was to go back and write another Zoë novel, but I got sucked into the world of espionage and have stuck with that. —Rick Porter, HollywoodReporter, 29 Oct. 2025

This interplay between exploration and espionage continues today, even when the surface of the world has been almost completely explored. —Literary Hub, 28 Oct. 2025

In television, Fu is a writer on Peacock’s upcoming espionage thriller The Copenhagen Test, starring Simu Liu and executive produced by James Wan. —Matt Grobar, Deadline, 27 Oct. 2025

In September, four former DPP staffers were jailed for espionage, including a former aide to President Lai, and a senior staffer to Joseph Wu, then foreign minister and now the head of the NSC. —Charlie Campbell, Time, 23 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