Spy glossary

Top intelligence officers have helped us create this glossary to share the tricks of their tradecraft. You’ll learn the difference between blowback and playback, dead drop and dangle, mole and microdot. Get this spy lingo right and you might even pass for an intelligence officer yourself.


As an agent, you work secretly for an intelligence service, offering secrets or operational support. While the FBI calls certain officers “agents,” most intelligence services prefer “officers.”

Agent handler

Your job is to manage (or “run”) an agent operation, which might include recruiting, instructing, paying, debriefing, or advising your agent.


You’ll need an alias—a false identity—to conceal a genuine one in the physical or digital worlds.


As an expert in your field, your job is to obtain crucial insights from intelligence, then write reports and give presentations to spymasters.


If you think you’re being watched, you’ll need to check without revealing your suspicion. You’ll need to conduct anti-surveillance: Drills to find out if people are watching you, without letting them know you know.


A secret source of information or operational assistance, usually an agent, but occasionally someone who’s totally unaware they’re aiding an intelligence service.


You can’t expect the world to take you at face value. People are going to check. Thoroughly. So you need backstops: the names and addresses of front companies that support your legend.


Trust the British to come up with such an eccentric, understated nickname for an intelligence officer.

Black bag operation

In a black bag operation, you break into a building to collect intelligence. You might have to pick locks, clone keys, crack safes. Survey and photograph. Plant listening devices. The name comes from the black bags burglars often use to carry their tools.

Black operation

“It wasn’t us.” That’s the official line on black ops. These are missions so sensitive they have to be deniable: The people at the top must be able to say they never knew. So if you’re discovered, it’ll look like you were working for some private group or organization. You’re on your own.


If something goes wrong with your covert operation, the consequences for those responsible may be disastrous. That’s blowback. A term coined by the CIA.


You need to move fast. Get out now, while you can. Why? Your mission or identity has been fully discovered. You’re blown.

Bona fides

Good faith? No thanks. This is espionage. If you want me to believe you are who you say you are, or that you have the clearance you claim, I’ll need cold, hard proof. I’ll need credentials. I’ll need your bona fides.

Brush contact

Some of the most important meetings in espionage last less than a second. A brush contact is barely contact at all: a moment’s jostle on a busy platform, two strangers passing on the street. Just enough to exchange something—a word, an envelope, a key. It’s so swift and subtle, even a trained surveillance team can miss it.


You’ve slipped up. Or someone else has. Either way your identity has been compromised.

Car Pick Up (CPU)

You’re waiting on a dark street and hear a gentle rumbling. A vehicle rolls up slowly, and swift as a shadow, you’ve vanished inside. The meeting—a car pick up—begins.

Case officer

The CIA term for an agent handler.

Chicken feed

Minor intelligence of no operational worth that an agent or double agent passes to a foreign intelligence service to prove their value.


A cipher scrambles your message into nonsense by substituting (and adding to) the letters in it. For someone to read it, they’ll either need the key or to be skilled at cryptanalysis.

Clandestine operation

An operation so secretive that the whole thing is designed to remain unknown and deniable.

Clandestine premises

See Safe house


Classified information is protected by law from public view, because a government feels it’s too sensitive to reveal. To get to it you’ll either need the right security clearance or another, less official way in.


You’re always aiming to stay clean: undetected, unsuspected. That way, you’re able to acquire and pass on information free from surveillance.


A forger of identity documents. “You’ll need a passport for your next assignment,” says one of your superiors. “Go and see the cobbler.”


You’re in a tight spot and don’t know who might be listening in. Luckily, you and your colleagues have a predefined code—a system of words that represent other words—to protect your communication and yourselves.


Uh oh. Some aspect of your operation, asset, or cover has been uncovered— compromised. You better think fast.

Concealment device

Need to hide secrets? Put them in something that looks ordinary: a suitcase with a false bottom, a hollowed-out coin, a USB flash drive. The best concealment devices are things that you carry with you every day.


You’re not part of an intelligence service, but you’re knowingly talking to someone who is. They describe you as conscious—in on what they really do.


Everyone knows everyone else is spying on them. So intelligence services devote a lot of energy to counterintelligence: thwarting foreign spying operations (which includes flushing out traitors).


This is the use of teams to watch for followers. Think of it as surveillance on surveillance.


You need a cover to mask the fact that you work for an intelligence service. Sometimes it’s just a false name. Other times you might need to carry business cards. In extreme cases, you’ll need a full-on legend.

Covert operation

The last domino falls—but no one saw the first one go. A covert operation is a hidden operation designed to influence events in a foreign, probably hostile, place. Everyone sees the result. But no one knows you created it.


The art of deciphering coded messages without being told the key.


You are a mathematical master of making and breaking codes.


The development of a relationship with an intelligence target (prior to recruitment) during which an intelligence officer explores the target's motivations to spy.


You need to get vital information to someone. But if they’re seen with you, their cover will be blown. So how do you get from A to B? You use C: a cut-out. A third party both of you trust, but whose presence won’t alert the enemy.


One way to catch fish is to dangle bait in the water. And one way to collect intelligence is to dangle an officer in front of the enemy. If the enemy bites, you’ve got a double agent on the inside, someone to gather secrets or spread disinformation. You may also use a dangle to identify enemy officers with the intent of removing them from your country.

Dead drop

How to pass something to someone who it’s not safe to meet? How about a dead drop site? A secret location where you can leave it for them to pick up later.


Breaking a code, with or without a key.

Deep cover

You’re diplomatic cover is so complete that even your colleagues in the embassy don’t know that you’re an intelligence officer.


If you want to get out of your country, you could defect to an opposing one. Defectors sometimes gain entry to their new country by offering valuable intelligence.


The operation is extremely sensitive and those in government don’t want it linked back to them. So you make it deniable. You set it up in a way that if a higher-up is ever asked, they can plausibly say they knew nothing.

Diplomatic cover

You’re both an intelligence officer and a diplomat. The cover gives you a reason for being in the target country as well as diplomatic immunity, including safe passage home, if you get blown.


One way to disrupt the activities of an enemy intelligence service is to spread disinformation: falsehoods, rumors, and fake stories. (Not to be confused with misinformation, which is unintentionally false.)

Double agent

A very risky position. You’re pretending to work for one intelligence service, while secretly working against it for another one.

Dry clean

Dry cleaning gets rid of spots. So if you think you’ve been spotted, that’s what you do: carry out measures to see if you’re being surveilled. (See also Anti-surveillance and Countersurveillance)

Ears only

You’re dealing with material so sensitive it must not be committed to writing.


A hidden mic. A bugged phone. There are many ways to eavesdrop—to listen in to (supposedly) private conversations.

Eyes only

Information that may be read but not discussed, or that can only be shown to specific people.


As an intelligence officer you need to master the subtle art of elicitation: drawing out valuable information from a target.


How do you protect your data? Encrypt it with a cipher. If you want to read it again you’ll need to decrypt it with a key.


A secret rescue operation to bring an agent, defector or intelligence officer (and sometimes his or her family) out of immediate danger and into a safe zone.

False flag operations

Operations designed to look like the work of another nation. Pirates flew the original “false flags” to fool the ships they were about to attack into believing they were friendly.

Front organization

The best smokescreens make no smoke. One way to keep your operations secret is to act through a front organization, usually a business, that no one knows you control.

Going gray

How do you get into a building you don’t have clearance for? Or catch conversations you’re not meant to hear? By going gray: looking and acting in a way that blends you into your surroundings.


This is information or means that an agent handler can use to control an agent.

Honey trap

That attractive stranger smiling at you from across the bar: possible romance, or a honey trap ready to seduce secrets out of you? They may even have been sent by your own side, to test your loyalty. The KGB named their male seducers ravens and the females swallows. Honey—but not so sweet.

Human Intelligence (HUMINT)

Spying is often about personality not physicality. HUMINT is intelligence gathered through personal contact with agents.


A member of the Illegals Program, a network of Russian sleeper agents in the US, who were arrested in 2010.


Most soldiers are stationed on the front line or behind their own lines. Not you. As an intelligence officer you infiltrate behind enemy lines, usually to gather intelligence for your spymasters or to help an agent escape danger.


This is your bread and butter. Intelligence is valuable, often secret information. And countries will go to great lengths to protect or steal it. (The word can also refer to the world of espionage as a whole.)

Intelligence cycle

Intelligence goes around in a cycle:

  1. Planning: Politicians decide what they need to know in discussion with spymasters.
  2. Collection: Intelligence officers collect the target information through a range of operations.
  3. Analysis: Analysts pore over what’s been collected, connect the key details with what they already know, and create useful intelligence.  
  4. Dissemination: Spymasters discuss the new intelligence with the politicians. They plan future operations to collect more, if that’s what’s needed. And the cycle begins again.
Intelligence officer

You work for an intelligence service, gathering or analyzing intelligence with the ultimate goal of helping your government and nation.

Intelligence operative

The heart of an intelligence organization, you’re involved in an array of operations, from servicing dead drops to setting up safe houses.


In secure, encrypted systems sometimes the same key—usually a string of letters and numbers—locks and unlocks your data. And sometimes the sender and recipient have different keys, which makes life even safer. Protect any keys that unlock important data: If your enemies find the key, you’re stuffed.


If you need a legend, you must be going in deep. It’s a sophisticated cover that amounts to an entire artificial life history (and supporting documents) to fool even determined counterintelligence professionals.

Lightning contact

See Brush contact

Limited hangout

What to do if news gets out about your operation? You could try a limited hangout: Shutting down further enquiry by giving away a portion of the truth and making an apology.

Live drop

You have secrets or money to exchange with an agent. How do you do it? Sometimes the safest thing is to meet face-to-face. That’s a live drop. Very different from a dead drop.


Why spy? You might want to get paid. Or you believe in the cause you’re helping. Perhaps you were blackmailed into it. Or maybe it makes you feel important. Most agents are motivated by one or more of these: Money, Ideology, Coercion, Ego. In short, MICE.


A microdot is an image or a whole page of text shrunk down to the size of a period, so as to escape notice by the enemy. (See also steganography)


You are employed by an intelligence service, but you’re passing secrets to the enemy. Often moles are recruited before they even work for their target service, making them even harder to spot than most agents.

Morse code

You have a message for someone, but normal communication isn’t an option. Luckily you know Morse code. You send each letter as a unique combination of “dots” and “dashes”— maybe flashing a torch, or tapping it out over a radio.


Acting without any assistance; you’re so exposed you might as well be naked.


The first rule of espionage: No one should know anything they don’t need to. Information can leak in all sorts of directions. So keep a tight lid on it. Tell people exactly what they need to know—and no more.

Numbers station

A shortwave radio station used to broadcast coded messages to an operative in the field. All you have you to do is tune your radio and know how to interpret the code.

One-time pad

The emperor of encryption, the one-time pad is unbreakable if used properly. Only you and the receiver have the pad, or key, needed to encrypt and decrypt the message. And it’s randomly generated. To read the message, an enemy would have to get hold of the pad.

Open-Source Intelligence (OSINT)

Sometimes you don’t need be covert about it. OSINT is intelligence collected from overt, publicly available sources. Mainly the internet nowadays.


What are we here to do? Recruit someone? Recover intelligence? Go after something new? Once it’s got a specific goal, we call it an operation, one of the most important words in intelligence.

Operational security (OpSec)

If you want to keep hold of your secrets and identity, you’ll need good OpSec. That means hiding your IP address, not leaking any personal information, and keeping all your conversations private and not logged.

Personal surveillance detection

See Anti-surveillance


Your plaintext is your message. The thing you want to say, before it gets scrambled with a cipher.


No one around you knows it, but you’re not who you seem. You’ve been secretly placed in this situation to gather intelligence. You’re a plant—and from the seeds of your intelligence, a whole conspiracy might grow.


Fake intelligence. You supply false information. Your target thinks it’s real, and gives you something in return. The perfect trade—for you at least. That’s playback.


Biased information put out to promote a cause or point of view. If the source is obvious, it’s white propaganda. If it pretends to be from one side, but is actually created by its enemy, it’s black propaganda.

Recognition phrase

You’ve met a contact. But you need to be sure of who they are, and they’re thinking the same. So you each say a pre-agreed recognition phrase—a snippet no one else would find strange. Small talk with big meaning. (The CIA sometimes calls recognition phrases “paroles.”)

Recognition signal

Something to confirm a contact’s identity. The signal must be distinctive. Any random person might be carrying a brown leather bag, but it probably won’t be diagonally over their left shoulder.


You’ve spotted someone who could be useful to your service. But this isn’t the sort of role you can just advertise. You may want your potential agent to turn against their country. Recruitment is often the final step in a process, after spotting, targeting, cultivating, and assessing.  


Some secrets have to stay secret. That’s why many documents are redacted, meaning their most sensitive passages are deleted or blacked out. Even declassified documents from decades ago may have redactions. Some things only a few people can know.


If you’re worried your dirty dealings are about to be exposed, there’s only one thing to do: Sanitize. Get rid of anything incriminating. Burn it, purge it from the record, amend the documents. Keep yourself and your sources safe.

Safe house

There’s a target on your back, and you need a safe house—a secure, secret location to hide in. Just don’t expect luxury. Most safe houses look as ordinary as possible.

Signals Intelligence (SIGINT)

SIGINT is intelligence gathered by intercepting communications between people. Because such communications are often encrypted, cryptanalysis plays an important role in SIGINT.


As a sleeper agent you live in a foreign country as an ordinary citizen. You will only act if a hostile situation develops. You build up your legend every day, adding new layers, acquaintances, and experiences. You might live it for years.

Source handler

See Agent handler

Special operations officer

As a special ops officer you’ll need the skills to operate weapons and explosives, and a whole lot of courage. You’ll be taking on missions to gather intelligence and destroy targets in hostile environments.


Slang for intelligence officer. The primary meaning of spook is a ghost. Like them, intelligence officers operate in the shadows.


If you’re thinking of becoming a spy—and passing secrets to a foreign intelligence service—then you’re taking a big risk. Getting caught could mean a life sentence. (Note: The word “spy” is commonly used to mean an intelligence officer, which is confusing because in fact it’s the opposite.)


A specialist in counterintelligence (thwarting enemy spies).


You’ve made it to the top—you’re a leader of an intelligence service.


Two targets are about to meet in a public park. Your surveillance team performs a stakeout of the area—spreading out, assessing the dangers, covering exit routes. All without drawing any attention.


Your station is where you carry out your espionage work, maybe for a few hours, a day, or long-term. In any case—keep it under your hat.


Like a Russian doll for data. Steganography is hiding a message, image or file in another message, image or file. It may look ordinary but not if you look much closer. (For an example of steganography, see Microdot)


The most literal form of spying is surveillance: secret observation. It may be simple: you alone, watching a doorway from a café across the street. Or complex: a team on foot and in vehicles, tracking targets via camera and satellites. Just make sure those targets never know you’re there.

Surveillance aware

They know. You know they know. You can see it from their behavior. They’re looking at you looking. They’re surveillance aware.

Technical Intelligence (TECHINT)

Intelligence about weapons and equipment used by foreign armed services. If you know what your adversaries are capable of you can plan accordingly.

Technical operations officer

An officer who gathers intelligence by tapping phones, breaking into buildings, planting cameras, and other means.


Has anyone been sneaking around while you were away? You’ll know, because you set subtle traps (sometimes known as “tells”) to give intruders away. A hair along a drawer that will drop invisibly if someone disturbs it, perhaps. Or a microscope slide under the carpet that will shatter inaudibly if someone walks on it.


The array of methods and tools used in covert intelligence operations. Get the tradecraft right and you give an operation the best chance of success. Get it wrong and there’s every chance you’ll get blown.

Traffic analysis

Traffic analysis means gathering intelligence by recognizing particular patterns or discrepancies in intercepted messages. It allows you to infer things without needing to read the messages themselves.


If you’re the trigger in a surveillance team, your eyes are glued to the target, and it’s your job to report on their movements. Meanwhile the others stay back to avoid spooking the target.

Technical Surveillance Countermeasures (TSCM)

If there are listening devices or covert cameras in your office, you’ll need to flush them out. So you launch TSCMs (or “bug sweeps”) to detect, and frustrate, any electronic surveillance.


Uncle is intelligence community slang for headquarters. No one said espionage was funny.


Operations conducted using a false identity. Your cover identity might last a few hours or several years, depending on the operation.


It can be very tough to find a suitable agent. Suddenly, hope: a walk-in appears, a spy looking to betray their country and provide you with vital information.

Wallet Litter

If your fake wallet’s going to look like a real one, it needs wallet litter—receipts, travel documents, event tickets—to add convincing detail to your cover.

SPYSCAPE has also made a glossary of the hacking terms you need to know, in conversation with top hackers and security experts. Click here for more...