A few bits of slang from the allied trenches:
ARCHIE - Anti-aircraft fire or artillery piece
BRASS HAT- High-ranking staff officer
CRUMBING UP - De-lousing.
DIXIE- a large cook pot
EMMA-GEE- Machine gun.
FLAG WAGGER- Signaller.
GREY HEN- an earthenware rum jar.
HAYBURNERS- horse and mules
REST CAMP- A cemetery.