The word backpack is a noun. Backpack means (1) a bag carried by a strap on your back or shoulder.
Backpack is also a verb that means (1) hike with a backpack.
The following articles and web pages elaborate on the word backpack.
Visit this military supplies manufacturer directory for information about military supplies manufacturers and wholesalers in the United States. The photo on this page shows a camouflaged military backpack.
Browse this school supplies and equipment vendor directory for info about school supplies and equipment manufacturers and distributors in the United States. The photo on this page shows a backpack filled with school supplies.