rock rental
n.— «The dropped public records charge stemmed from what Sheriff’s Office spokesman Capt. John Fortunato called a “rock rental,” where someone loans an automobile in exchange for a rock of cocaine.» —“West Bank School Football Star Pleads Guilty To Drug Charge” by Joe Darby, Greg Thomas Times-Picayune (New Orleans, La.) Aug. 11, 1992. (source: Double-Tongued Dictionary)