A

    ABC
    American-British-Canadian talks in 1941
    Abwehr
    Intelligence service for the German Armed Forces - run by Admiral Canaris
    Accolade
    Operational code-name for Allied attempt to capture the Dodecanese Islands in the Agean.
    Acrobat
    Code name for British advance on Tripoli in 1941.
    Adlertag
    Code name for the day of intense German air attack on Britain (Eagle Day) 15th September 1940.
    AEF
    Allied Expeditionary Force
    A-Force
    British intelligence organization responsible for deception and espionage in the Mediterranean and Middle East.
    AK
    Armja Krajowa ("Home Army") - The Polish Resistance
    Aktion T4
    Extermination of mentally ill and handicapped patients by the Nazi authorities. (Named after Tiergartenstrasse 4, the address of Nazi Central Office in Berlin.)
    Allgemeine SS
    Standard branch of the SS, as opposed to the military or armed Waffen SS.
    Allies
    Those countries fighting against the Axis powers. i.e. Britain, France, USA, Canada, USSR etc
    Altreich
    Term used to describe Germany before the annexation of Austria.
    Amt Mil
    German Army intelligence organization which succeeded the Abwehr
    Anakim
    Code name for the Allied re-occupation of Burma in 1944.
    Anschluss
    German annexation of Austria in March 1938.
    Anti-Comintern Pact
    Agreement by Germany, Japan and Italy to oppose the Communist International organisation
    Anton
    Code name for the German occupation of Vichy France, November 1942 - later known as Atilla
    Anvil
    Operational code name for the Allied invasion of the South of France, August 1944.
    ANZAC
    Australia and New Zealand Army Corps
    Arcadia
    Code name for the first Anglo-American conference in Washington, December 1941.
    Argonaut
    Code name for the Anglo-American-Soviet conference at Yalta, February 1945.
    Argument
    Operational code name for Allied air attacks on German factories in February 1944.
    Aspirin
    British equipment used for jamming German Knickebein radar
    Atilla
    Code name for the German occupation of Vichy France, November 1942
    Atlantic Charter
    Anglo-American declaration that stated the countries aims for the outcome of the war.
    Aufbau Ost
    Operational code name for the German build-up of arms prior to the invasion of the Soviet Union
    August Storm
    Operational code name for the Soviet invasion of Manchuria, August 1945.
    Avalanche
    Operational code name for the Allied invasion at Salerno, September 1943
    Avonmouth
    Operational code name for the Allied attacks in Narvik, May 1940.
    Axis
    Alliance between Germany, Italy and Japan. Originally the Rome-Berlin Axis (i.e. a North-South line between the two capitals), later became the Rome-Berlin-Tokyo Axis.

B

    Bagration
    Operational codename for Soviet strategic offensive against the German Army Group Centre, June 1944.
    Barbarossa
    Operational code name for the German invasion of the Soviet Union in June 1941. (Barbarossa, or "Red Beard" was the nickname for Emperor Frederick I, who attempted to unify Germanic states in the 12th century.)
    Battleaxe
    Operational code name for the British offensive in North Africa intended to relieve Torbuk, June 1941
    Baytown
    Operational code name for the Allied landings in southern Italy, September 1943
    BCRA
    Bureau Centrale de Renseignements et d'Action - de Gaulle's secret intelligence service
    BEF
    British Expeditionary Force
    Benjamin
    Code name for British Jamming equipment to counter German "Y-Beams"
    Bernhard
    Operational code name for German scheme to counterfeit British bank notes and put them into circulation - began in 1942.
    Bertram
    Operational code name for the British deception operations prior to El Alamein offensive, North Africa October 1942
    Bestrafung
    Operational code name for German "punishment" air attacks on Belgrade, April 1941
    Blitzkrieg
    "Lightning War" - a term used to describe the rapid German invasions using fast, piercing armoured formations
    Bodenplatte
    "Base Plate" - Operational code name for the German air offensive against Allied airfields in north-western Europe, January 1945
    Bodyguard
    Operational code name for the deception operations intended to conceal Allied intentions in north-west Europe from 1944
    Bolero
    Operational code name for the build up of US forces in Britain prior to the invasion of France
    Bomb, The
    Slang term for the computers used at Bletchley Park, England, to decode German Enigma messages
    Brevity
    Operational code name for the British offensive in the Halfaya Pass, May 1941
    Brimstone
    Operational code name for the proposed Allied invasion of Sardinia, 1944
    Bromide
    Code name for British Jamming equipment used to counter German "X-Beams"
    Bulge, Battle of the
    Term used to describe the actions following the German offensive through the Ardennes forests in December 1944.
    Buzz Bomb
    Nickname for the German V-1 flying bomb

C

    Capital
    Operational code name for the recapture of northern Burma in 1944
    Case Green
    Operational code name for the intended German military invasion of Czechoslovakia
    Case Red
    Operational code name for counterstrike against France in the event of an attack on Germany from the West
    Case White
    Operational code name for the German invasion of Poland
    Case Yellow
    Operational code name for the German invasion of the Netherlands, Belgium and France
    Catapult
    Operational code name for the destruction of the French Fleet by the British in North Africa, July 1940
    Catchpole
    Operational code name for the US assault on the Marshall Islands, 1944
    CCS
    Combined Chiefs of Staff (Allies)
    Chain Home
    British air-defence radar
    Chastise
    Operational code name for the "Dam Busters" raid by 617 squadron RAF in May 1943, on the Mohne, Eder and Sorpe dams in the Ruhr area of Germany
    Chindits
    Long-range penetration troops (British and Gurkha) who worked behind the Japanese lines in Burma.
    CIGS
    Chief of the Imperial General Staff (British)
    Citadel
    Operational code name for the German attack on the Soviet forces near Kursk, July 1943
    Cobra
    Operational code name for the American breakout from Normandy in July 1944
    Cockade
    Operational code name for Allied deception operations intended to draw attention away from Normandy prior to D-Day
    Comintern
    Communist International organisation created to promote the spread of communism from the Soviet Union - disbanded in 1943.
    Commando Supremo
    Italian supreme command
    Compass
    Operational code name for British operations in Egypt against the Italians in December 1940
    COSSAC
    Chief of Staff, Supreme Allied Commander. HQ of the CCS in London.
    Crossbow
    Operational code name for Allied attacks on V-1 launch sites
    Crusader
    Operational code name for British attempts to relieve Torbruk beginning in November 1942

D

    D-Day
    The first day of the Allied invasion of Normandy - June 6th 1944 - D stands for "Day"
    Demon
    Operational code name for the British evacuation of Greece in April 1941
    Diadem
    Operational code name for Allied offensive in Italy towards Rome in 1944
    Division
    A basic army formation made up of between 12,000 and 18,000 men
    Domino
    British equipment used to counter the German Y-Beam (Y-Gerat) bombing system
    Downfall
    Operational code name for the planned Allied assault on Japan in 1945
    Dragoon
    Operational code name for Allied operations in the South of France formerly known as Anvil
    DUKW
    An amphibious truck used by the Allies. D=1942 (design date); U=Utility Vehicle; K=All Wheel Drive; W=2 powered rear axles
    Dynamo
    Operational code name for the British evacuation of Dunkirk in May/June 1940

E

    Eagle's Nest
    Name given to Hitler's mountain-top home at Berchtesgaden in the Bavarian Alps
    EAM/ELAS
    The Greek Resistance
    Einsatzgruppen
    German death-squads operating in occupied territories and carrying out mass-murders
    Elektra
    A German radio-navigational system
    Enigma
    German message encryption equipment
    ENSA
    Entertainments National Service Association - UK organisation for entertaining troops abroad.
    Etappendienst
    German naval intelligence department
    ETO
    European Theatre of Operations
    Eureka
    Code name for the Allied conference in Teheran Nov/Dec 1943

F

    Fahnenheid
    The oath of allegiance to Hitler sworn by the German Army
    Fall Gelb
    Case Yellow - Operational code name for the German invasion of the Netherlands, Belgium and France
    Fall Gruen
    Case Green - Operational code name for the intended German military invasion of Czechoslovakia
    Fall Rot
    Case Red - Operational code name for counterstrike against France in the event of an attack on Germany from the West
    Fall Weiss
    Case White - Operational code name for the German invasion of Poland
    FCNL
    French Comittee of National Liberation
    Feldgrau
    "Field Grey" - term used to describe the ordinary German soldier - from the colour of his tunic.
    Feldgendarmerie
    German military police
    Felix
    Operational code name for the German plan to capture Gibraltar in 1941
    FFI
    French Forces of the Interior
    FH
    Fremde Heere - German intelligence evaluation service
    FHO
    Fremde Heere Ost - German intelligence evaluation service - eastern section
    FHW
    Fremde Heere West - German intelligence evaluation service - western section
    Final Solution
    Name given to the German policy of genocide of the Jewish population
    Fischfang
    "Fish Trap" - Operational code name for the German counter attack on the Allied beachead at Anzio in February 1944
    Flash
    Code name for the assassination attempt on Hitler by the Schwarze Kapelle in March 1943 - where a bomb was placed on Hitler's aircraft.
    Flat Top
    Nickname for aircraft carrier
    Flintlock
    Operational code name for the US invasion of the Marshall Islands in January 1944
    Forager
    Operational code name for the US invasion of the Mariana Islands in June 1944
    Forschungsamt
    The intelligence service of the Luftwaffe
    Fortitude
    Operational code name for the Allied deception operations prior to the invasion of Normandy
    FUSAG
    First US Army Group - a fictitious army group under the command of General Patton which appeared to be based in south-east England prior to the Normandy landings and was intended to give the impression that the Allies were due to invade France via the Pas de Calais

G

    Galvanic
    Operational code name for the US occupation of the Gilbert Islands - November 1943
    GC&CS
    Government Code and Cipher School - based at Bletchley Park, England
    Gestapo
    Geheime Staatspolizei - the German Secret State Police
    GKO/GOKO
    Soviet State Defence Committee
    Gold
    Code name for one of the landing beaches in Normandy (in the British/Canadian sector) in the area of Arromanches
    Gomorrah
    perational code name for the RAF bombing of Hamburg in July/August 1943
    Goodwood
    Operational code name for the Allied breakout from Normandy via Caen in July 1944
    Gothic Line
    German defence line in Italy - north of Florence
    Granit
    Operational code name for the US operations in the Central Pacific - March 1944
    Greif
    Operational code name for the dropping of English-speaking German Troops wearing American uniforms behind the Allied lines in the Ardennes, prior to Hitler's last offensive in the west
    Grenade
    Operational code name for the US offensive in the Rhineland - February 1945
    Gustav Line
    German defence line in Italy - centred on Monte Cassino

H

    H2S
    British airborne radar used for identifying and locating ground targets
    Herbstnebl
    "Autumn Mist" - Operational code name for the German offensive in the Ardennes, December 1944 - Also known as The Battle of the Bulge
    HIWI
    Hilfsfreiwillige - German Army volunteer forces usually made up of Soviet volunteers
    Holocaust
    The act of genocide carried out by Germany on the Jewish population of Europe
    Huff-Duff
    HF/DF - High Frequency / Direction Finding - British radio detection system used to pinpoin the direction of broadcasts from German submarines and ships and thus locate the transmitting craft
    Humint
    Human Intelligence - Intelligence gathered by spies and informers (as opposed to signals intelligence or SIGINT)
    Husky
    Operational code name for the Allied landings in Sicily - July 1943

I

    IA
    Indian Army
    Ichi Go
    Operational code name for the Japanese offensive operations in Eastern China - April 1944
    IFF
    Identification Friend or Foe - Radio device fitted to aircraft in order to identify the aircraft as friendly when approaching home radar stations
    INA
    Indian National Army

J

    Jael
    Operational code name for the Allied deception operations in Europe - later called Plan Bodyguard
    JCS
    Joint Chiefs of Staff - US high command, representing US Army and Navy
    JIC
    Joint Intelligence Committee - Top intelligence body in both USA and UK
    JPS
    Joint Planning Staff - British military planning organization
    JSC
    Joint Security Control - US organization, subordinate to the JCS responsible for security/codebreaking/deception operations
    Jubilee
    Operational code name for the British-Canadian raid on Dieppe - August 1942
    Jupiter
    Operational code name for British plan to invade Norway
    Juno
    Operational code name for one of the D-Day landing areas in Normandy between the Provence River and the town of St. Aubin sur Mer - principally a Canadian landing area

K

    Kempei
    Japanese military police
    Knickebein
    "Crooked Leg" - German navigational system using radio beams to guide bombers
    Kondor Mission
    German espionage operation based in Egypt
    Konstantin
    Operational code name for the German occupation of the Balkans areas previously occupied by Italian forces - September 1943
    Kriegsmarine
    The German Navy
    Kripo
    Kriminalpolizei - German criminal police department
    Kutusov
    Operational code name for the Soviet offensive against German forces in the Kursk Salient - July 1943

L

    LCA
    Landing Craft Assault
    LCS
    London Controlling Section - British organisation responsible for military security, cryptanalysis and deception operations
    Lebensraum
    "Living space" - Term used by the Nazis to refer to their plans for territorial expansion, particularly in the East
    Lend-Lease
    US policy of supplying the Allies with equipment and materials in exchange for payment in kind or return of undamaged equipment following the war.
    Liberty Ships
    Cargo ships mass produced in the USA from pre-fabricated components
    Lichtenstein
    German airborne radar used for nightfighting
    Lightfoot
    Operational code name for the British offensive at El Alamein - October 1942
    Locarno Pact
    Agreement signed in 1925 by Britain, Germany, France, Belgium, Italy, Poland and Czechoslovakia, guaranteeing international boundaries and re-affirming the Treaty of Versailles
    LRDG
    Long Range Desert Group
    LRPG
    Long Range Penetration Group
    LSD
    Landing Ship Dock
    LSG
    Landing Ship Gantry
    LSI
    Landing Ship Infantry
    LSS
    Landing Ship Stern-chute
    LST
    Landing Ship Tank
    Luftwaffe
    The German Air Force

M

    MAAF
    Mediterranean Allied Air Force
    MAC
    Mediterranean Air Command
    Magic
    Code name for US code breaking operations against the Japanese
    Maginot Line
    Series of sophisticated French fortifications positioned along France's eastern borders consisting of steel and concrete anti-tank emplacements and pillboxes
    MAN
    German armed anti-nazi resistance group, named after the MAN engineering works in Bavaria
    Manhattan Project
    Cover name (actually 'Manhattan Engineer District') for the development of the atomic bomb in the USA
    Maquis
    Name given to groups of the French Resistance (after a type of foliage in Corsica, behind which resistance fighters on the island used to hide)
    Marita
    Operational code name for the German attack on Greece in April 1941
    Market Garden
    Operational code name for the Allied operation intended to establish a bridgehead across the river Rhine at the town of Arnhem in the Netherlands
    Menace
    Operational code name for Allied operations at Dakar - September 1940
    Merkur
    "Mercury" - Operational code name for the German air attacks on Crete - April 1941
    Message Personnels
    System used to communicate with members of the Resistance on the European mainland from Britain by using coded messages broadcast on BBC radio
    MI5
    British security service responsible for national security matters within the United Kingdom
    MI6
    British security service, otherwise known as the Secret Intelligence Service, responsible for collecting foreign intelligence relating to national security
    MI9
    British service responsible for assisting escaped prisoners of war
    Milice
    Paramilitary police force of Vichy France (Milice Francaise)
    Millennium
    Operational code name for the RAF bombing of Cologne - May 1942
    Mincemeat
    Operational code name for British deception operation in April 1943 where false operational plans were planted on a corpse and left floating off the coast of Spain - The Germans intercepted and believed the plans, which gave the impression that an Allied invasion of Greece was iminent, whereas the real invasion was planned for Sicily
    Moonshine
    British device used on aircraft to fool German radar into seeing far more aircraft than actually existed
    MT
    Motor Transport
    MTB
    Motor Torpedo Boa
    MTO
    Mediterranean Theatre of Operations
    Mulberries
    Transportable floating harbours constucted from hollow concrete, towed to the D-Day landing sites and used to offload equipment and supplies during the Normandy landings

N

    Nazi
    An abbreviation for 'National Sozialistiche Deutsche Arbeitpartei' the NSDAP, literally translated means National Socialist German Workers Party.
    Neptune
    Operational code name for the Allied D-Day Normandy beach landings - the naval assault phase of Operation Overlord
    Nest Egg
    Operational code name for the British re-occupation of the Channel Islands - May 1945
    NID
    Naval Intelligence Division
    NKVD
    Narodni Komissarat Vnutrennykh Del - Soviet People's Comissariat of Internal Affairs - the predecessor to the KGB, the Soviet internal security organisation
    Noball
    Operational code name for Allied air attacks on German V-weapons sites in 1944.
    Nordlight
    "Northern Lights" - Operational code name for the German attack on Leningrad in 1942
    Nordwind
    "North Wind" - Operational code name for the German offensive in the Alsace - Winter 1944/45

O

    Oboe
    Code name for British radio-navigational aid used by RAF bombers
    Octagon
    Code name for the second Quebec conference between Roosevelt and Churchill - September 1944
    OFEC
    Office of Foreign and Economic Co-ordination (USA)
    Oflag
    Offizier-Lager - "Officer Camp" German prisoner-of-war camps for Allied officers
    OKH
    Oberkommando der Heeres - High Command of the German Army
    OKL
    Oberkommando der Luftwaffe - High Command of the German Air Force
    OKM
    berkommando der Kriegsmarine - High Command of the German Navy
    OKW
    Oberkommando der Wehrmacht - High Command of the German Armed Forces
    Olive
    Operational code name for the Allied assault on the Gothic Line, Italy - August 1944
    Omaha
    Code name for one of the US Normandy beach landing areas used on D-Day, the site was between Coleville and Vierville
    OPD
    Operations Division of the US Department of War
    OSS
    Office of Strategic Services - US military intelligence and special operations agency
    Overlord
    Operational code name for Allied operations in Normandy and North West Europe, beginning with Operation Neptune on D-Day, 6th June 1944.
    OWI
    Office of War Information (USA)

P

    Pact of Steel
    Alternative name for the Rome-Berlin Axis
    Panzer
    "Armour" - became a general term for German tanks (the correct term for tank being Panzerkampfwagen - PzKpfw) and also used to describe armoured actions
    Panzergrenadier
    German mechanized infantry
    PNCL
    Polish Committee of National Liberation
    Pedestal
    Operational code name for a relief convoy to Malta - August 1942
    Plunder
    Operational code name for British/Canadian offensive across the Rhine on 13th March 1945
    Pluto
    Pipe Line Under The Ocean - pipeline laid under the English Channel to supply oil to the Normandy invasion forces in 1944
    Pointblank
    Operational code name for the Allied bombing offensive against Germany from 194
    Priceless
    Operational code name for Allied operations in the Mediterranean theatre of operations in 1943

Q

    Quadrant
    Code name for the first Quebec conference (Churchill & Roosevelt)- August 1943
    Quicksilver
    Code name for deception operations involving General Patton's fictitious FUSAG
    Q-Ships
    Armed Allied decoy ships used to lure Axis submarines to the surface, where they could be attacked by gunfire

R

    RAAF
    Royal Australian Air Force
    RAF
    Royal Air Force (Britain)
    Rainbow
    Code name given to US war plans drawn up for various scenarios
    RAN
    Royal Australian Navy
    RCAF
    Royal Canadian Air Force
    RCN
    Royal Canadian Navy
    RDF
    Radio Direction Finding
    Reckless
    Operational code name for US operations in Hollandia, New Guinea - April 1944
    Red Army
    The Soviet armed forces
    Reichstag
    The German Parliament
    RFSS
    Reichsfuehrer SS - "Reich Leader SS" the formal title of Heinrich Himmler
    RIN
    Royal Indian Navy
    Ring
    Operational code name for Soviet offensive against German army at Stalingrad - January 1943
    RN
    Royal Navy (Britain)
    RNZAF
    Royal New Zealand Air Force
    RNZN
    Royal New Zealand Navy
    RSHA
    Reichssicherheitshauptamt - "Reich Security Main Office" - orgainisation created by Himmler to coordinate all German security and police departments including the Gestapo, Kripo and SD.
    Rumyantsev
    Operational code name for Soviet counter offensive at the battle of Kursk, following operation Citadel - August 1943

S

    SA
    Sturmabteilungen - "Storm Troopers" - Hitler's unofficial army of thugs (aka Brownshirts) - disbanded after the blood purge of 1934
    Schwarze Kapelle
    "Black Orchestra" - term used to describe a group of conspirators within the German Army who plotted to overthrow Hitler. The Schwarze Kapelle came close to assassinating Hitler on July 20th 1944.
    SD
    Sicherheitsdienst - "Security Department" - The Nazi Party security service, intelligence gathering and counter-espionage wings of the RSHA headed by Reinhard Heydrich
    SEAC
    South East Asia Command (Allies)
    Sealion
    Operational code name for the planned German assault on Great Britain in 1940/41
    SHAEF
    Supreme Headquartes Allied Expeditionary Force
    Shingle
    Operational code name for the Allied landings at Anzio - January 1944
    SIM
    Servizio Informazioni Militari - the Italian military intelligence agency
    Sledgehammer
    Operational code name for a planned Allied invasion of France in 1942
    SOE
    Special Operations Executive - British organisation responsible for training and co-ordinating the operations of partisan groups in occupied countries
    SS
    Schutzstaffeln - "Protection Units" - The principal elite organisation of the Nazi party which consisted of the Allgemeine (General) SS and Waffen (Armed) SS, the latter forming military divisions as part of the Wehrmacht. The SS also included organisations such as the RSHA.
    Stavka
    The highest political-military authority of the Soviet Union
    Sword
    Code name for the D-Day landing beaches of Lion-sur-Mer - June 1944
    Symbol
    Code name for the Allied conference at Casablanca - January 1943

T

    Taifun
    "Typhoon" - Operational code name for the German push towards Moscow - September 1941
    Ten-Go
    Operational code name for the Japanese naval operations at Okinawa and Iwo Jima beginning April 1945
    Terminal
    Code name for the Allied conference in Potsdam - July 1945
    TF
    Task Force
    Thunderclap
    Operational code name for the Allied bombing of Dresden - February 1945
    Tidal Wave
    Operational code name for the US bombing of the Romanian oilfields of Ploesti - August 1943
    Tiger
    1. Operational code name for the German advance through the Maginot Line on the French border - June 1940 2. Operational code name for a British convoy to Egypt in May 1941
    Torch
    Operational code name for the Allied landings in North West Africa - November 1942
    Totalize
    Operational code name for the Canadian advance towards Falaise, France - August 1944
    Trident
    Code name for the third Allied conference in Washington - May 1943
    Tripartite Pact
    Formal agreement of alliance between Germany, Italy and Japan - an expansion of the Axis nations - signed 27th September 1940

U

    U-Boat
    Unterseeboot - "under sea boat"- Abbreviated name for German submarines
    U-Go
    Operational code name for the Japanese push towards India from Burma - March 1944
    Ultra
    Code name and security caveat given to decoded messages and intelligence originating from German Enigma encrypted sources
    Uranus
    Operational code name for the Soviet counter-offensive at Stalingrad to surround the German 6th Army - November 1942
    USAAF
    United States Army Air Force
    USN
    United States Navy
    USS
    United States Ship
    Utah
    Code name for D-Day landing area near Les Dunes de Vatreville, Normandy
    UXB
    Unexploded bomb

V

    V-1
    The first of the operational German weapons of reprisal or "Vergeltungswaffen" - the V-1 was a pilotless flying bomb powered by a pulse-jet engine and carried a 850kg (1875lb) high-explosive warhead, and had a range of up to 200km
    V-2
    Also known as the A4, the successor to the V-1 was a long range rocket powered by liquid oxygen and alcohol, it had a 975kg (2150lb) high-explosive warhead and a range of 320km
    V-3
    Long-range smooth-bore gun designed to fire shells with up to 10kg (22lb) high-explosive warhead and a range of 93km - never very successful as most installations were destroyed by bombing before they could be used
    Valkyrie
    Operational code name for the Schwarze Kapelle plot to overthrow the Hitler regime - July 1944
    Varsity
    Operational code name for the Allied crossing of the Rhine using airborne troops - March 1945
    V-E Day
    Victory in Europe Day - 8th May 1945
    Vichy France
    French regime set up in collaboration with the Germans following the fall of France in 1940 - headed by Marshal Petain and based in the city of Vichy it governed the southern half of France until its dissolution in 1944
    V-J Day
    Victory over Japan Day - 15th August 1945
    Volkssturm
    The German Home Guard
    Vulcan
    Operational code name for the Allied offensive in Tunisia - May 1943

W

    WAAC
    Women's Auxiliary Army Corps (USA)
    WAAF
    Women's Auxiliary Air Force (British)
    Waffen SS
    The branch of the SS which formed military fighting divisions
    Wehrmacht
    The German armed forces - headed by the OKW
    Weserubung
    "River Exercise" - Operational code name for the German invasion of Denmark and Norway - April 1940
    Window
    Also known as Chaff - metallic foil strips dropped from bombers to give the appearance to German radar of mass formations of aircraft
    Wintergewitter
    "Winter Storm" - Operational code name for the unsuccessful German attempt to relieve the 6th Army at Stalingrad - December 1942
    Wolfschanze
    "Wolf's Lair" - code name for Hitler's headquarters near Rastenburg in East-Prussia
    WPD
    War Plans Department (US)
    WRNS
    Women's Royal Naval Service (British)
    WVS
    Women's Voluntary Service (British)

X

    X-craft
    A type of midget submarine
    XX-committee
    British intelligence organisation used to feed false information to Germany e.g by the use of double-agents
    X-Gerat
    German bomber radio-navigational equipment

Y

    Y-service
    British signals staff responsible for the interception of enemy radio and telephone messages

Z

    Zeppelin
    Operational code name for deception operations in the Balkans in 1943
    Zitadelle
    "Citadel" - Operational code name for the German attack on the Soviet forces near Kursk, July 1943
    Zyklon-B
    Commercial name for the prussic acid gas used in German extermination camps