n. 背包

[ noun ]
a bag carried by a strap on your back or shoulder
<noun.artifact>

Knapsack \Knap"sack`\, n. [D. knapzak; knappen to eat + zak a
bag. See {Knap}, v. t., and {Sack}.]
A case of canvas, leather, nylon, or other sturdy fabric,
fitted with straps, for carrying on the back the food,
clothing, or other supplies for a soldier or a traveler; as,
to hike up the mountain with lunch in a knapsack.
[1913 Webster +PJC]

And each one fills his knapsack or his scrip
With some rare thing that on the field is found.
--Drayton.