A word that means any kind of drug including marijuana, heroin, meth, cocaine...
It's been used for a long time to describe any kind of illegal drug.
Some people think it only refers to heroin. This is incorrect as many rappers and people who live in drug infested areas call marijuana, crack and heroin dope and those who sell them as dope dealers.
Lyrics from the song Dopeman by NWA:
"From a kid to a G, it's all about money
10-piece, 4-10, base pipe comes free
If people out there ain't hip to the fact
If you see somebody gettin' money 4 crack