A knapsack, often mounted on a lightweight frame, that is worn on a person's back, as to carry camping supplies.
A piece of equipment, often containing life-support devices, designed to be used while being carried on the back: a parachute in a backpack; an astronaut's backpack.
verb: -packed, -pack·ing, -packs.
intransitive verb
To hike while carrying a backpack.
transitive verb
To carry in a backpack.
derivatives
bacḱpacḱer
noun
bacḱpacḱing
noun
The American Heritage® Dictionary of the English Language, Fourth Edition