knapsack

Short definition from Wiktionary

Noun

1. 1
   (In UK, dated or archaic). A case of canvas or leather, for carrying items on the back. 1936, Arthur Ransome, Pigeon Post, ch 3. « All but Nancy carried knapsacks, with sandwiches and thermos flasks of tea. Peggy’s knapsack held Nancy’s provisions as well as her own, for on Nancy’s shoulders, instead of a knapsack, was a pigeon-basket... »
2. 2
   A set of values from which a subset is chosen.

Verb

1. 1
   To go hiking while burdened with a knapsack, usually overnight or for longer.