Similar to the Cold Shoulder, the cold backpack is when you are trying to find a seat on the bus and people put their baggage next to them on the seat to stop you from stealing their one seated glory.
When you are riding a public transportation system, such as a school bus, and someone who wants to sit alone nonchalantly pushes their backpack to the outside of the seat to shun and/or reject the possibility of sitting with them.
Guy on Cell Phone walking onto bus: "Yes Mom I did my homewor... hold on this freshman bitch just gave me the cold backpack
, I'm gonna have to empty a leg
on this douche bitch.”
Douche Bitch:(thinks to himself) "Oh Shart