double agent

/ˌˈdʌbəl ˌeɪdʒənt/

Other forms: double agents

A spy who is pretending to work for one country while really working for that country's enemy is called a double agent.

If you were hired in North Korea to spy on the United States, but you were secretly supplying confidential information about North Korea to the US government, you could call yourself a double agent. Some double agents work for organizations like the CIA, the US Central Intelligence Agency, and their field of expertise is known as "counterintelligence." In some cases, a spy becomes a double agent after their loyalty is turned against their home country.

Definitions of double agent

1. noun

   a spy who works for two mutually antagonistic countries
   type of:

   spy, undercover agent

   (military) a secret agent hired by a state to obtain information about its enemies or by a business to obtain industrial secrets from competitors