The criminal world in the 18th century had a language all it's own known as 'cant'. These were slang terms. Whilst they covered everything you can imagine, these are just a few of the terms used in the sex industry for Madams, pimps and prostitutes:
Madams were known as:
buttock brokers, Abbess, Aunt, Mother
Pimps were known as:
Beard Splitters, bulls, cockbawd
Prostitutes were known as:
covent garden nuns, drabs, doxies, casevrow, crackish, fens, bats, blowers… and my favourite quicunque vault.