Third-person singular simple present indicative form of backpack.(verb)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "backpacks" in a sentence
"You tend to miss all the neat-o reminders and such that go home in backpacks from the classroom."
"They were in backpacks and on desks and in hands, some even read during recess."
"Silly me – it does make it easier for people who want to blow up subway trains to have the ability to bring explosives in backpacks – (i.e. 7/7 – London)."