Green’s Dictionary of Slang

an unmarried young woman.

1821		Egan Life in London (1869) 52: Waltzing with the angelics at my Lady Fubb’s assembly.
1821		W.T. Moncrieff Tom and Jerry I iv: This what do you call it? – this cover-me-decently, was all very well at Hawthorn Hall, I daresay; but here, among the pinks in Rotten-row, the lady-birds in the Saloon, the angelics at Almack’s [...] it would be taken for nothing less than the index of a complete flat.
1835		G. Kent Modern Flash Dict.
1848		Flash Dict. in Sinks of London Laid Open.