GAD - The Graphics and Authentication Division of the Office of Technical Service, responsible for operational disguise and false documentation capabilities for the CIA.

GAMBIT - A highly sensitive disguise developed for the CIA with the help of their Hollywood consultant. It was first used in Indochina in 1971.

GCHQ - Britain's sigint agency, Government Communications Head Quarters.

GDGS - General Directorate of General Security (Direction Générale de la Sûreté Générale, المديرية العامة للأمن العام). Lebanon’s intelligence agency.

GESTAPO (The) - The Geheime Staatspolizei (literally : Secret State Police) was the secret police of Nazi Germany and German-occupied Europe. It was created by Hermann Göring and then passed under supervision of Schutzstaffel (SS) national leader Heinrich Himmler.

GHOST SURVEILLANCE - Extremely discreet and seemingly omnipresent surveillance, working mostly out of the view of the target.

GIA - An underground group in Algeria.

GID - Iraq's main intelligence organization, Da' Irat al Mukhabarat al-Amah.

GHOUL - Agent who searches obituaries and graveyards for names of the deceased for use by agents.

GONE TO GROUND - To take evasive action in order to avoid further attention. To "lay low."

GOTTLIEB, Sidney - Spy

GOUZENKO, Igor - Spy.

GOVERNMENT COMMUNICATIONS SECURITY BUREAU (The) - (GCSB) New Zealand's analog to GCHQ, GCSB is charged with promoting New Zealand's national security by collecting and analyzing information of an intelligence nature.

GRANVILLE, Christine - Spy.

GRAYMAIL - Threat by a defendant in a trial to expose intelligence activities or other classified information if prosecuted.

GREAT SEAL BUG (The) - Also known as the Thing. A highly successful Soviet mission in which a listening device was implanted within a copy of the Great Seal of the United States which was presented as a plaque to the United States Ambassador to the Soviet Union, W. Averell Harriman.

GREY ZONE - Part of the five terrains of warfare : land, sea, air, space, and now cyberspace.

GRU - Russian military intelligence, the Glavnoye Razvedyvatelnoye Upravleniye, equivalent to the US's DIA. It is now also known as G.U.

GSS - Israel's security service (also called Shin Beth).

GTsST - Main Center for Special Technology, a unit of the GRU (Russian military intelligence) that is highly involved in cyberattack programs, including the enabling of influence operations. Suspected perpetrators of the NotPetya and South Korean Olympics hacks amongst others, and of trying to disguise their attacks as another country's misdeed.

GUAN-XI - An access agent for China's intelligence agency.

GUOANBU - One of China's security services.

GUILLAUME AFFAIR (The) - Espionage scandal.

GUSTAV WEBER - Hitler's double, used by the Fuhrer's bodyguards to stymie the Allies as to his whereabouts. Shot in the forehead immediately after Hitler's death.