Your mom is strong but ugly – she’s missing one breast and it’s replaced with a glass one – and even though she’s hideous, she’s still nice because she fills the glass breast with everyone’s favorite flavored drink for the neighborhood children.

i.e. Pregnant. ‘Big with child’ was a common phrase in English-speaking countries until the 19th century, although it’s now mostly restricted to the Caribbean and some areas of the USA.

Nothing to do with this guy:

Corvus, or “The Raven”, is a constellation.

In one story, Corvus was a raven whom Apollo sent to get him some water. Instead Corvus waited for figs to ripen. Much like Sweeney.

In the middle of Sackville Street there’s a statue of Sir John Gray, an Irish Protestant who edited and owned the Freeman’s Journal, and who supported land reform.

The food here is typically exotic, and its abundance — emphasised by Eliot’s lack of punctuation — is a nod to Sweeney’s physicality. He’s all flesh; unlike the heroic Agamemnon, who’s driven by higher ideals than gorging on food.

The English name for the Río de la Plata, a large estuary in South America. It’s exotic, sub-tropical – a pretty appropriate place for the moon to be thinking on here.

Alas, I am struck deep with a mortal blow.

So says Agamemnon in Aeschylus' Agamemnon, struck dead by his wife Clytemnestra.

“Sweeney Among the Nightingales” is also about a murder, and this epigraph sets up the pattern of neo-Classical irony that runs throughout the rest of the poem. Sweeney is a mock-heroic figure – he has not, like Agamemnon, fought bravely at Troy, but has instead, as described in ‘Sweeney Erect’ ignored a woman’s epileptic fit.