E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Those who live by plunder by night. Those who live by plunder in the daytime are Heavy Horsemen. These horsemen take what they can crib aboard ship, such as coffee-beans, which they call pease; sugar, which they call sand; rum, which they called vinegar, and so on. The broker who buys these stolen goods and asks no questions is called a fence. (See Captain Marryat: Poor Jack, chap. xviii.)