2. In many places a roach is a burnt joint, usually but not necessarily the very last end, it can be halfway finished and still be called a roach, the principle being on that it has already been smoked from.
3. Roofies, R2s, rohypnol, pills that can be used to get fucked up on usually with alcohol, or in many cases used as a date rape drug, effects can last for hours, with the user remembering little or nothing.
2. Save that roach for later I'm fucking high.
Wheres that roach that we were smoking earlier?
3. Dude, I just bought two roach pills from Brigg.
Hey can I have one of them roaches?
Usually a "roach" has lousy credit and can't afford to buy, or he comes in regularly and talks shit how he will buy, but never actually buys a car because of variuous resons, like credit, money, or his indecisivness.
This roach has been in here every other day, and he still makes up excuses not to buy. Stay away from him.