Salient
Bulging outwards.
Sentries
Soldiers on guard duty.
Bramble
A prickly bush.
Gunnery
Multiple guns firing at the same time.
Poignant
Involving a feeling of deep sadness.
Ranks of Grey
The author refers to soldiers in the trenches.
Nonchalance
The state of being completely calm or relaxed.
Sun-dozed
Made sleepy by the sunbeam.
Glozed
Concealed.
Loath
Unwilling or reluctant.
Pucker
Contract into wrinkles.