Definitionen
1.NounA knapsack, sometimes mounted on a light frame, but always supported by straps, worn on a person’s back for the purpose of carrying things, especially when hiking, or on a student's back when carrying books.
2.NounA similarly placed item containing a parachute or other life support equipment.
3.VerbTo hike and camp overnight in backcountry with one's gear carried in a backpack."I spent a month backpacking in the Rockies."
4.VerbTo engage in low-cost, generally urban, travel with minimal luggage and frugal accommodation.
5.VerbTo place or carry (an item or items) in a backpack."Astronauts backpack oxygen during spacewalks."