IPA: /ˈrʌk.sæk/
KK: /ˈrʌkˌsæk/
A type of bag that is carried on the back, often used for hiking or traveling, and usually has two straps.
She packed her rucksack with all the supplies for the camping trip.
Rucksack → The word originates from the German 'Rucksack', where 'Ruck' means 'back' and 'Sack' means 'bag'. Thus, a rucksack is a bag designed to be carried on the back.
Think of a 'bag' ('Sack') that you carry on your 'back' ('Ruck') — that's what a rucksack is.
No commonly confused words.