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 of espionage

• 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

Last year, Vinatier was also charged with espionage, according to the FSB — a criminal offense punishable by 10 to 20 years in prison in Russia. —Sylvie Corbet, Los Angeles Times, 8 Jan. 2026

Aldrich Ames, a former CIA case officer arrested by the FBI in 1994 and sentenced to life in prison for espionage, died in custody on Monday, according to a spokesperson for the US Bureau of Prisons. —Josh Campbell, CNN Money, 7 Jan. 2026

The law was based on fears of espionage after the attack, which were generally unfounded. —Nollyanne Delacruz, Mercury News, 7 Jan. 2026

This type of data enables phishing impersonation and corporate espionage at scale. —Kurt Knutsson, FOXNews.com, 6 Jan. 2026

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