Term used for heroin by the people who do it. It's called the boy for a couple reasons. 1) Because it's associated with the word Ron (short for heroin). 2) Just like coke is referred to as that girl or da girl, heroin is called da boy or that boy.

The biggest LAD out there, DA BOY is equivalent to being a black belt in pulling girls, hosting partys, and pretty much being awesome in everything he does.