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Akofern: From Armee-Fernsprechkommandeur, commander of a German telephone section.
Akofunk: From Armee-Funkerkommandeur, commander of a German wireless section.
Akonach: Commander of a German signal service.
Albatros B-Type(s) : A series of unarmed German reconnaissance biplanes in service when the war began.
Albatros C-Types (s) : A series of German two-seater armed biplanes used for reconnaissance and occasional light bombing, first introduced in 1915.
Albatros D-Types(s) : A series of single seat German fighter aircraft first introduced in 1916.
Albatros J-Type(s) : A series of two-seater German ground attack aircraft first introduced in 1917.
Albratros W-4: A German seaplane fighter aircraft first introduced in 1916.
ALH: Australian Light Horse.
Alleyman: British nickname for a German, derived from the French Allemagne.
Allies, The: The alliance of nations fighting against the Central Powers.
Ally Sloper's Cavalry: British nickname for the Army Service Corps.
AMB: Armoured Motor Battery, a British armoured car unit.
AMC: 'Armed Merchant Cruiser', basically large, speedy passenger ships requisitioned by navies and armed to Cruiser standard. All sides used AMCs as auxiliaries to their official navies.
Amiens Hut: A canvas over poles structure found in British camps.
Ammos: British nickname for boots.
AMS: Army Medical Staff.
AMTC: Acronym for Allied Maritime Transport Council.
Ansteckmagazin: A 25 round (extra large) magazine for the German rifle.
Antonio: Nickname for Portuguese troops.
ANZAC: Both an official acronym for the 'Australian and New Zealand Army Corps', an army made from the Australian Imperial Force and the New Zealand Expeditionary Force and an informal term for any soldier from said army. The Anzacs fought in Gallipoli, Palestine and the Western Front.
Anzac Cove: The tiny foothold on the Gallipoli Peninsular held by Allied (mainly Australian and New Zealand Anzac) soldiers against Turkish troops from April 25th 1915 to early 1916.
AOC: Army Ordinance Corps.
AOK: Armee-Oberkommando, German Army Command.
AP: Aid Post.
APM: Assistant Provost Marshall.
AQ: Adjutant and Quartermaster General.
Archie: Anti-aircraft fire.
Area Shoot: Carpet bombardment.
Arent: Telegraphic listening device used by the German army; name after the designer.
Arko: Artillerie-Kommandeure, German artillery command (first used in 1917).
Armée Navale: The French Navy.
Armistice: An official and arranged halt in hostilities to allow peace negotiations. The Armistice between the Allies and Germany which ended the war was signed on November 11th 1918 and valid for 36 days; it was regularly renewed until peace treaties were signed.
Armlet: Fabric band worn around the arm to designate a position or duty.
Armoured Cruisers: With both side and deck armour and heavy weapons these ships were used as scouts for battleships, but were made obsolete by the creation of Battlecruisers.
Armstrong Hut: Canvas and wood collapsible hut used by the British.
Armstrong Whitworth FK-3: British two-seater bomber introduced in September 1916.
Armstrong Whitworth FK-8: British two-seater reconnaissance/bomber aircraft introduced in late 1916.
ARS: Appareil respiratoire spéciale, French gas mask.
ASC: Army Service Corps.
Asiatic Annie: Slang for the large Turkish guns along the Dardanelles.
Asquith: Derisory nickname for the infamously unreliable French safety match.
Asto: Abhörstationen, German telegraphic listening stations.
ASW: Anti-submarine warfare.
Attrition: Destroying your opponent’s resources through constant pressure.
Australian Imperial Force: The Australian army.
Auxiliary Commerce Raiders: Warships of the German navy disguised as unarmed merchant vessels in order to attack shipping. They had success far in excess of their numbers.
AV: Arbeitsverwendungsfähige, German medical designation for those only fit for labour.
AV7 Panzerkampfwagon: The only German produced tank of the First World War; only a few were ever made.
AVC: Army Veterinary Corps.
Aviatik B-Types: Two-seater German biplane used for reconnaissance in the early part of the war.
Aviatik C-Type: Two-seater armed German reconnaissance biplane first used in early 1915.
Avro 504: British two-seater biplane used for reconnaissance and light bombing, introduced before the war.
AWL: Absent without leave.
AWOL: Absent without official leave.
Ayrton Fan: Device for dispersing gas when waved, basically fabric on a staff.