- Jesus, meek and humble ... — this "prayer" to the Sacred Heart is actually taken from two different prayers. The first two lines are from the Litany of the Sacred Heart of Jesus, and the last two lines from the prayer O Sacred Heart of Jesus, I Trust in Thee.
- Sunday beads — a special set of Rosary beads reserved for using at Sunday Mass, as opposed to the humdrum day-to-day ones.
- starry nimbus — in RC iconography the Virgin Mary is frequently depicted with a halo formed of stars.
- campanulate — bell-shaped. (("used chiefly in Botany & Zoology" – OED.))
- bread-box — ? the passage abounds with sacred objects and descriptions, so a possible reference to an altar tabernacle.
- girandole — (("an ornamental branched wall candleholder, usually incorporating a mirror" – Collins.))
- box-stairs door — ? the door, apparently, to an enclosed staircase.
- Old Horny — nickname for the Devil. ((OED.))
- walk three times ... — a not uncommon superstition in Ireland regarding Protestant churches. eg: (("You walk around the 'Black' church three times – you'll meet the devil himself! The 'black church' is a protestant church in Dublin's northside" – Irish superstitious phrases.))
- I promise you in the unfathomable mercy ... — from the 12th promise Jesus vouchsafed to St Mary Alocoque concerning the Sacred Heart devotion. ((Socías, Handbook of Prayer, 1995.))
- Lusitania — Jim confuses the word with a placename (Lusitania = poetical name for Portugal), but actually it is the sinking of RMS Lusitania, an Atlantic passenger liner, that the newsboy is calling. The sinking, by a German U-boat, had occurred that afternoon, May 7 1915, off the southern Irish coast.
- When are the other boys coming? — from the recruitment poster Doyler tore earlier < Ch3.2.
- clothed with the sun ... — from the Book of Revelation. (("And there appeared a great wonder in heaven; a woman clothed with the sun, and the moon under her feet, and upon her head a crown of twelve stars." Revelation 12:1.))
- Oft in the stilly night — from the song sung by Mr Doyle earlier < Ch3.2.
- embarkation leave — (("the customary 48 hours' leave granted to all men who are warned for foreign service" – Hansard 1917.))
- lying head-and-tails — ((lie heads and tails: "to sleep heads to head-rail and foot-rail alternately" low colloquial – Partridge HS.))
- picture palaces — (("old-fashioned name for cinema" – Collins.))
- ticking — (("strong cotton fabric, often striped, used esp. for mattress and pillow covers" – Collins.))
- Sir Redvers Buller — popular British general during the Boer War, later ridiculed for incompetence. ((Wikipedia.))
- smell ... glue-pot — smell of seminal fluid. < Ch2.3.
- old horny — punning Old Horny (the Devil) and old horny (("the penis" low – Partridge HS.))