Is “Knapsack” a Scrabble word?
Yes
KNAPSACK
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Knapsack
noun
1.A case of canvas or leather, for carrying items on the back.
2.A set of values from which a subset is chosen.
Synonyms: backpack, rucksack
verb
1.To go hiking while burdened with a knapsack, usually overnight or for longer.
“My sleeping bag fell off my backpack into the water, while we were knapsacking up the mountain.”
Synonyms: backpack