Men marched asleep. Many had lost their boots
But someone still was yelling out and stumbling,
And watch the white eyes writhing in his face,
The iambic pentameter is dominant but occasional lines break with this rhythm – line sixteen in the third stanza – reflecting the strangeness of the situation.
outstripped Five-Nines refers to the type of shell being used, 5.9 calibre, which were not up to the speed of other shells used.
like a devil’s sick of sin is a right in your face simile, whatever you think a devil looks like, one that has gone beyond the pale.
bitter as the cud is a term used in farming, where cud is the half digested food of ruminants which is chewed again to make it digestible. The suggestion is that the blood coming up from the lungs has to be chewed by the poor dying man. A sobering image. Note the first line of Owen’s poem Anthem For Doomed Youth – What passing bells for these who die as cattle?
zest means enthusiasm.
ardent means passionate
The latin ending is perhaps a gentle reminder of many a slogan, many a motto and maxim held dear by clubs, military units, teams and families as an expression of belief and ideals. These are often displayed in latin which was of course the language of the ancient Romans.