Sentence:  All the time this conversation had been going on, we had been scudding along at as brisk a pace as Mouldy's <WSD>slipslop</WSD> boots would permit, up the Old Bailey and by Newgate, (where my companions having inquired whether I knew at which door they brought people out to hang 'em, and received from me an intimation that I did not, kindly paused for a moment to enlighten me,) out into Ludgate Street, and across the road into turnings and twistings dingier than any I had yet met with. 
Meaning of the word marked with <WSD> tags:  Tending to flop or slide about.