knapsack
UK[ˈnæpsæk]US[ˈnæpsæk]
n
a bag made of strong material and carried on the back, used especially by walkers and climbers.
Etymology
the word 'knapsack' entered english in the early 17th century from low german 'knappsack' or dutch 'knapzak'. the low german term is a compound of 'knappen', meaning 'to eat' or 'to bite' (related to the sound of chewing), and 'sack', meaning 'bag'. thus, its original literal sense was a 'food bag' or a bag for carrying provisions. the term was adopted into english military and travel vocabulary, where it generalized to mean any sturdy bag carried on the back for holding supplies, shedding its exclusive association with food.
Analysis
the word is a loanword from german and is not productively segmented into meaningful morphemes in english.
Examples
he packed a water bottle and a sandwich in his knapsack for the day hike.
the soldier's knapsack contained all his essential gear.
she rummaged through her knapsack to find her keys.