Definition of backpack:

a bag carried by a strap on your back or shoulder

Synonyms of backpack:

back pack, haversack, knapsack, packsack, rucksack, satchel, travel bag, bag, handbag, briefcase

Opposite/Antonyms of backpack:

stay, wait, await, hang, hang on, remain, rest, linger

Sentence/Example of backpack:

The young man picked up his backpack, and together they walked out of the shul.