EFC - Expeditionary Force Canteens for troops, located behind the lines. Precursor of NAAFI.
Emma Gee - Machine gun.
Emma Pip - Military policeman.
Enfilade - To fire down a trench or at a row of men lengthways, rather than crossways.
Erk - Junior rank of air-fitter in RFC/RAF.
Ersatz - Below the expected, or required, standard, e.g. ersatz coffee made from chicory and/or acorns. German reserves (German for an inferior substitute; [1875])
Estaminet - Simple bar cum café typically offering cheap wine and/or brandy and omelette et frites.
Exaspirator - Early box type gas mask.
Excused duty - Sick note for illness not requiring hospitalisation.
