Knapsack /(?)/

Knap·sack

Knapsack

n.
  1. 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.
    And each one fills his knapsack or his scrip With some rare thing that on the field is found.