KNAPSACK Meaning of KNAPSACK in English ■ noun a soldier's or hiker's bag with shoulder straps, carried on the back.OriginC17: from Mid. Low Ger., from Du. knapzack , prob. from Ger. knappen 'to bite' + zak 'sack'. Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004