AEF – American Expeditionary Force.
ANZAC – Originally the Australian and New Zealand Army Corps, although the contingents from the two countries were later separated, with the more numerous Australians eventually settling as a corps of five divisions, which enjoyed a unique reputation for self-regard and Pommy-bashing as much as for its high skills of aggressive patrolling and combat efficiency.
BEF – British Expeditionary Force to France and Belgium.
Casualties – This term includes dead, wounded, missing and prisoners. It must not be confused, as it too often is, with the total of dead (which in this war usually ran at something like a third of the total casualties).
chevaux de frise – A row of metal or timber spikes held together on a timber frame, used as a military obstacle for several centuries before barbed wire was invented, but anachronistically still in use during the Great War.
GHQ – General Headquarters of the BEF, i.e. the command staff of first French and then Haig.
HE – High Explosive.
Kitchener or ‘New’ Armies – The mass mobilization of ‘hostilities only’ volunteers in 1914–15 which produced a majority of the BEF of 1916, largely replacing the regulars and territorials who had started the war. In late 1916 the supply of volunteers had dried up, so conscription was at last introduced in Britain.
der Millionenkrieg – War fought by millions of men, which was one of the most striking innovations of 1914–18. Some armies had technically fielded over a million men at a time in years before 1914, but only in the Great War would such large numbers be present on the same front.
No man's land – The ‘neutral’ ground between two opposing lines of trenches. It was a notoriously dangerous place to be, since it was potentially under fire from both sides, but on many nights it was surprisingly heavily populated by wiring parties and offensive or defensive patrols.
Pom (noun), Pommy (adj.) – Derogatory Australian term for a Briton.
Schwerpunkt – The key point on the battlefield. German doctrine recommended that an absolute maximum of resources should be concentrated there, even if that left other important points underprovided.