Updated: DECEMBER 24, 2018
A merkin is essentially a pubic wig. Merkins have a long history and have been used since the 15th century. Originally, they were used by men and women to cover up the evidence of sexually transmitted infections and parasites, such as syphilis and crabs. Male actors also sometimes wore merkins when portraying female characters, as females were forbidden from acting on stage.
More About Merkin
Although they went out of style for a while, merkins seem to making a comeback today. Actresses, for instance, use them when trying to realistically portray characters who should have more pubic hair than themselves.
Merkins aren't just for actresses, though. Men dressing in drag and ordinary women can add a little fun in the bedroom with decorative merkins made from real or synthetic hair, feathers, or fur.