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

Such aggression could continue invisibly despite a ceasefire, allowing one party to pre-position capabilities for future attacks or to conduct espionage without triggering traditional monitoring mechanisms. —Josefina Echavarria Alvarez, The Conversation, 3 Dec. 2025

Earlier this fall, a team of security experts at the AI company Anthropic uncovered an elaborate cyber-espionage scheme. —Matteo Wong, The Atlantic, 25 Nov. 2025

Pollard, a former American intelligence analyst, spent 30 years in prison on espionage charges after being found to have passed critical security documents to Israeli intelligence in the 1980s. —Paul Goldman, NBC news, 21 Nov. 2025

The episode raised questions about Britain’s ability to balance the need to defend itself from espionage and interference while remaining economically engaged with the world’s second-largest economy. —Christian Edwards, CNN Money, 18 Nov. 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