- ☆ backpack [bak′pak΄ ]n.1. a kind of knapsack, often attached to a lightweight frame, worn by campers or hikers2. a piece of equipment, as a radio transmitter, used while being carried on the back3. an astronaut's pack used in extravehicular activities to provide a life support system and locomotion4. a scientific instrument pack attached to people, wild animals, etc. to monitor their physical conditions, locations, etc.vi.to hike wearing a backpackvt.to carry in a backpackbackpackern.
English World dictionary. V. Neufeldt. 2014.