Green’s Dictionary of Slang

a prostitute who works in the City Road, London, itself part of the parish of St Luke’s.

1909

J. Ware Passing Eng. of the Victorian Era 8/1: ‘What are you doing here? you ain’t a Angel – you’re only a Sluker’ (i.e., St Luker, from the Parish of St Luke, in the City Road, which is considered at the Angel as socially below Islington, as it is comparatively depressed in its physical want of elevation in comparison with the Angel, which is quite at the top of the hill).