24 Must-Know Secret Spy Terms for the Undercover World

John le Carré, the mastermind behind espionage classics such as The Spy Who Came in From the Cold and Tinker, Tailor, Soldier, Spy, left an indelible mark on spy fiction. His greatest legacy might be the language he introduced through his characters. Le Carré is recognized for coining or popularizing espionage slang, including the term mole, which refers to a deeply embedded agent. Interestingly, the spy community may have borrowed this term from le Carré, who transitioned from British intelligence to a celebrated writing career.

The term mole is just one example of spy jargon that has infiltrated mainstream culture. Explore 20 intriguing spy terms that can help you navigate the shadowy realm of covert operations.

Pocket Litter

To pass a quick identity check, spies carry pocket litter—personal items such as a driver’s license, boarding pass, or handwritten note—to reinforce their fabricated identity.

Blowback

In espionage, blowback refers to the unintended consequences of covert actions, which can harm the spy or their nation. (For instance, assassinating a leader could result in significant blowback.) Originally, the term described the backward ignition of gases or explosives, but it has since evolved into a key concept in spy terminology.

Dead Drop and Concealment Device

Initially, dead drop referred to a simple dive without flips or twists. However, since the 1950s, it has been adopted by spies to denote a secret spot for exchanging information or items without direct contact. To further conceal these items, agents might use a concealment device—a seemingly ordinary object with a hidden compartment, as defined by the CIA—to avoid detection.

Safehouse (Safe House)

A safehouse, in spy terminology, is a secure and undisclosed location free from threats. It serves as a refuge for spies to hide, safeguard informants or valuable assets, and meet associates without risking exposure. Historically, the term safehouse dates back to the 1500s, where it referred to a type of prison.

Chicken Feed

In the early 19th century, chicken feed became slang for a trivial amount of money or something insignificant. In espionage, it refers to non-critical information shared with adversaries to build trust without revealing classified secrets.

Kompromat

Kompromat refers to compromising materials gathered by Russian intelligence to manipulate or blackmail individuals, such as evidence of infidelity. The term blends kompro- from komprometirujuščij (compromising) and mat- from material (material).

Exfiltration

Exfiltration involves covertly extracting a valuable asset or defector from hostile territory. Originating in 1878, the term initially referred to the process of filtering something out, as noted by the Oxford English Dictionary.

Pavement Artist

Originally, pavement artist referred to street artists who created chalk masterpieces on sidewalks. In spy jargon, it describes an operative who shadows a target on foot, often in outdoor settings.

Triple Agent

While double agents deceive one side about their allegiance, a triple agent deceives two parties about their true intentions. This term can also describe an agent who feigns loyalty to one nation while secretly serving another.

Dangle

According to the CIA Spy Speak Glossary, a dangle is someone deliberately made available to a foreign intelligence agency for recruitment, only to serve as a double agent for their home country.

Walk-In

A walk-in is an individual who voluntarily approaches a rival intelligence agency with valuable information, without prior solicitation.

Rolled-Up

If a covert mission is compromised and exposed by the opposition, it is described as being “rolled-up.”

Sleeper Agent

A sleeper agent is a spy who lives an ordinary life until their government decides to “activate” them for a mission.

Flaps Well Down

This outdated expression referred to an operative (typically British) who was lying low due to fears for their safety.

Picnic

In espionage, a “picnic” refers to an assignment location considered low-risk or straightforward.

Ghoul

In espionage, a ghoul is an operative who uses the names of deceased individuals to craft fake identities for covert missions. The term, which also denotes a malevolent spirit haunting graveyards or abandoned areas, originates from 18th-century Arabic folklore.

Sheep Dipping

As reported by The New York Times, sheep-dipping involves embedding an agent within a civilian organization to gather intelligence on that group or related entities.

Come in From the Cold

A spy returning to a relatively normal life after prolonged isolation and deep cover is described as “coming in from the cold.” John le Carré brought this term into prominence with his 1963 novel The Spy Who Came in From the Cold.

Walk Back the Cat

Walk back the cat refers to retracing the steps or events that led to a specific outcome. For instance, if a spy turns traitor, operatives might analyze their actions to pinpoint where things went wrong. Similarly, if a foreign government makes an unexpected decision, intelligence agencies might investigate the preceding events.

HUMINT

HUMINT, an abbreviation for “human intelligence,” refers to intelligence collected through direct human interaction rather than technological means. It’s said that former CIA director William Webster was unfamiliar with this and other spy jargon when he assumed his role in 1987 and had to familiarize himself. (Webster preferred to call himself The Judge.)

Wet Work, Wet Stuff, and Double-Tapped

Wet work describes missions involving assassination or murder, likely alluding to the bloodshed involved. These operations are also called wet stuff. If a target is shot twice, they are said to have been double-tapped. Ideally, such actions avoid any unintended consequences.