Noun
a bag carried by a strap on your back or shoulder
Source: WordNetFlashlight, cap, colored pencils, magnifying glass, paperblock and granola bar in a child´s back pack. Source: Internet
Not defending Yeti at all however anyone who does anything outdoors for more than the once ina while pack a few drinks for the kids soccer games understands the difference between a Yeti type cooler and you $30 coleman back pack cooler. Source: Internet
Remember this wonderful school back pack (cartable) I spotted in the street? Source: Internet
The back pack of data shoe horns itself in and that's where we look first. Source: Internet