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C3: The lowest class of fitness in the British army; the term evolved into slang for something useless.
CA: corps d'armee, French army corps.
Cable: Telephone cable.
Cable-Trench: A deep trench dug just to carry telephone cables.
Cadre: A battalion's reserve of officers and men who hung back during an attack; there were enough to operate as an effective unit if the main attack was wiped out. Also known as First Reinforcements or Battle Surplus.
Cage: Prisoner of war camp.
Cagoule: French smoke helmet.
Calendrier : French 'racquet' grenade.
Camion : French lorry.
Camouflet : In counter-mining operations, the chamber and mine used to detonate and fill in enemy tunnels.
Canary: British instructor temporarily working at a base instead of the front lines; named after the yellow brassard they wore.
Cap comforter: Woollen stocking cap.
Carnet B: French list of 'disruptive' individuals, including spies, pacifists and political radicals, who were to be arrested in the event of a war. The list was never used and 80% of those on it joined the armed forces.
Case shot: Anti-personal artillery shell, usually filled with shrapnel, chain or pellets and fired at short range.
Cat: A tractor.
Caudron G-III: Unarmed French reconnaissance biplane in use at the war’s beginning.
Caudron G-IV: French reconnaissance/bomber plane introduced in November 1915; also used by
Caudron R-11: French escort fighter/light bomber planes introduced in 1918.
CB: 'Confined to Barracks', military punishment.
CCS: Casualty Clearing Station.
CD: 'C Department' of the German War Ministry; actually War and Pensions.
C de G: Croix de Guerre.
CED: Corps Expéditionnaire des
CEF: Canadian Expeditionary Force.
CEP: Corpo Expedicionario Portugués, Portuguese Expeditionary Force of the Western Front.
CES: Commisioned Escort Ship; a civilian craft requisitioned, armed and out into military service, but smaller than an AMC.
Central Powers: Initially the alliance of
CGT: Confédération Générale du Travail, General Confederation of Labour in
CGS: Chief of General Staff.
CHA: Commander, Heavy Artillery.
Chambre de repos : French dugout.
Char: British slang for tea.
Char d'assaut : French tank or armoured vehicle.
Charger: The clip holding rounds for insertion into a magazine rifle.
Chats: Australian nickname for lice.
Chaser(s) : US nickname for the French Chasseurs Alpins (mountain infantry).
Chauchat: French 8mm light machine gun which became the French army’s close support weapon; also used by the early AEF.
Cheminement: French 'approach' trench.
Cherb: British colloquialism for beer.
Cherry Nobs: Slang British Military Police, after their red caps.
Chevron: Marks of rank and position on the uniforms of the British army.
Chinese Attack: A fake attack whereby an artillery bombardment would, usually prompting enemy troops to rush out from cover to man their trenches against an expected attack, whereby the artillery would begin again.
Chink: British slang for Chinese.
Chipperow: British slang for 'be quiet' or 'shut up'.
Chit: British term for a written message.
Chloride of Lime: Chemical used to purify water in trenches.
Chokey: British slang for prison or a minor punishment
Chub: Another British slang for 'be quiet' or 'shut up'.
Chumpy: Slang term for the effects of shell shock.
CID: Committee of Imperial Defence.
Cigognes : 'Storks', an elite French aircraft fighter unit named after the flying storks painted on their planes. They were given the best equipment, featured heavily in propaganda and were all aces.
CIGS: Chief of Imperial Staff.
Circus: British nickname for a German aircraft unit.
Class Corps: An unit of the Indian Army recruited from a single race or tribe.
Class Company Regiment: A British Imperial unit comprised of companies each recruited from one race or tribe.
Clink: British nickname for prison.
CM: Committee on Public Information.
CO: Commanding Officer.
Coal box: Any shell explosion causing a cloud of black smoke.
Coffin Nails: Cigarettes.
Colis-Postal: Both French for something delivered by parcel post and French slang for an incoming shell.
Comics Cuts: Intelligence Summaries.
Communication Trench: small trenches usually built at right angles to regular trenches to allow 'protected' communication between them.
Con camp: Convalescence camp.
Concertina Wire: Coiled, usually barbed wire used to create defensive entanglements.
Conchie: A conscientious objector.
Concussion Shell: An artillery shell which explodes upon impact showering the surrounding with shrapnel.
Convoy System: The practice of merchant ships sailing in groups protected by armed vessels; this was a response to submarine warfare.
Corduroy Surface: A temporary road surface created by laying bundles of wood across a road, probably derived from the similarity to the material.
Conscientious Objector: Someone refusing to fight (usually in an army) for religious, moral or ethical reasons.
Cook's Tour: Soldiers slang for a VIP's trip around the trenches.
Cordite: An explosive.
Corkscrew: The metal posts which supported wire entanglements; they had a twisted base, allowing them to be screwed into the ground.
Cossack post: Advanced cavalry patrol.
Covering party: Any group defending a front line working party.
CP: Collecting Post.
Crapaud: French slang for the German disc grenades, British slang for a French trench mortar.
Crapouillot: Either a French trench mortar or trench howitzer.
Crater: The hole caused by a shell detonation or mine.
CRE: Officer Commanding Royal Engineers.
Créneau de Canardeur: French sniper's hole or loophole.
Creeping Barrage: A slowly moving artillery barrage acting as a defensive curtain for infantry following closely behind.
Crib: Reinforced metal and wood box/bridge used by tanks to cross wide streams or trenches.
Cricket Ball: British and ANZAC slang for a spherical grenade.
Cruiser: A class of ship. Originally a British concept from the 1880s, Cruisers were smaller than battleships but still armed, armoured and capable of offensive ocean-going operations. Most nations adopted the concept.
Cruiser Rules: Unofficial naval convention where the crew and passengers of civilian vessels where allowed to abandon ship before it was sunk.
Crump: Shell or shell burst.
CSM: Company Sergeant-Major.
CSRG: Chauchat-Sutter-Ribeyrolles-Gladiator, the Chauchat, a French light machinegun.
C-Stoff: German term for mono- and tri- chlormethyl chloroformate gas.
CT: Communication Trench / Com Trench.
Curtain Fire: A barrage intended to create a 'curtain' of fire between friendly and enemy troops.
Cushy: Happy or easy.