Doing a different drug, other than your preference, while you wait for your primary drug to become available.
Where did all the (drug name) go?
I don't know but I had to drug sub for this!
Why the hell did you do that? I thought you hated that stuff.
It was the only thing they had!
a building subcontractor whose business is financed by the drug trade and money laundering activities, primarily accomplished by using illegal drug money, paying labor (usually illegal labor) with the illegal cash and not deducting the payroll charges from gross income; net income is overstated and the overage is taxed resulting in the illegal drug money suddenly becoming legal and "laundered"; to accomplish this he must have legitimate customers that he usually steals from honest hardworking subcontractors.
Joe the Plumber's business went bankrupt because he was competing against Trey's Waterworks; Trey is a drug sub.