Older coded street slang for Heroin. It'
s typically used in contrast to White
Girl which often refers to cocaine, or less often Fentanyl, and also Heroin. One example of where you can hear or read it used is in the book
Pimp: The Story of My Life, an auto-biographical novel written by Iceberg
Slim. In the back you can find examples and definitions that give context to other slang terms used throughout the novel and audiobook as well.