c. 1600, from Low German Knapsack (16c.), probably from knappen "to eat" literally "to crack, snap" (imitative) + Sack "bag" (see sack (n.1)). Similar formation in Dutch [..]

1.)Another term for back-pack, yet not quite as popular. 2.) Used mostly in the early-mid 1900's by New Yorker's.

A term intended to offend. Used as an insult, meant to replace terms like shithead, fuck-bag, asshole.

The female teabag. when a girl gingerly plops her funbags on another fellow's head or face. Usually resulting in a smile.

a bag for food and clothes that you carry on your back

Component of the M1941 pack system. The knapsack was used to store clothing and personal items that a Marine might need during a prolonged transit, voyage or field problem. Assault troops typically di [..]

To see a knapsack while dreaming, denotes you will find your greatest pleasure away from the associations of friends. For a woman to see an old dilapidated one, means poverty and disagreeableness for her.   

(US) A case of canvas or leather, for carrying items on the back. (cryptography) A set of values from which a subset is chosen.