Term used to describe items that were stolen during the process of being shipped to the store. These items were usually boosted by the truck drivers and then sold on the street at a heavily discounted price. The drivers would keep the cash for themselves. This black market usually allowed poorer people in the inner city to gain access to items they would have never been otherwise able to afford.
My grandfather grew infinitely cooler in my eyes when I found out how he was able to afford my grandmother's diamond engagement ring on his factory worker's salary:
"I got it real cheap. It fell off the back of the truck."