'knapsack' originates from German, specifically the word 'Knappsack', where 'knappen' meant 'to bite' and 'Sack' meant 'bag'.

'Knappsack' changed from the German word 'Knappsack' and eventually became the modern English word 'knapsack'.

Initially, it meant 'a bag for provisions', but over time it evolved into its current meaning of 'a backpack or rucksack'.