Found
Keats quotation
From Keats's "To Homer"—but Rossetti misquotes it. Keats wrote "There is a budding morrow in *the* midnight," about poetic inspiration. Rossetti changes it to suit a darker purpose.
Love deflowered
Victorian code for lost virginity. The woman has been sexually ruined—in 1850s terms, unmarriageable, socially dead.
Under one mantle
Bundling—courting couples wrapped together in a cloak. A recognized pre-engagement intimacy that here led to sex and abandonment.
Locked heart
She's disassociating. He's trying to rescue her from prostitution, but trauma has severed recognition. She can't acknowledge him or their past.