Backpack/ˈbækpæk/ Definition 1 of 2Pro Tip 1/3Backpack Types Backpacks vary by use: school, hiking, travel, or fashion. Her stylish leather backpack turned heads at the airport. Pro Tip 2/3Carrying Method Backpacks are typically carried on both shoulders for comfort. He adjusted the backpack on his shoulders before boarding the bus. Pro Tip 3/3Size Implication A 'backpack' often implies a medium-sized bag, larger than a 'daypack'. She needed a bigger backpack for her week-long hike.