merkin

The Oxford Companion To The Body traces the merkin back to 1450, a time when the bidet was a distant prospect and personal hygiene fell well short of the mark.
Pubic lice were common - so some women, fed up with the constant itching, just shaved the lot off and then covered their modesty with a merkin.
Prostitutes, too, were frequent wearers. In the days before penicillin, it didn't take long to become infected with sexually transmitted diseases. They knew it was no work, no pay, and didn't want to scare the customers off with their syphilitic pustules and gonorrhoeal warts. So the merkin was used as a prosthesis to cover up a litany of horrors.
The Oxford Companion recounts an amusing tale of one gentleman who procured the disease-riddled merkin of a prostitute, dried it, gave it a good comb and then presented it to a cardinal, telling him he had brought him St Peter's beard. Some prostitutes even used them to give their nether regions a bit of razzle-dazzle. So a natural brunette could offer differing collars and cuffs to demanding customers.