'backpack' originates from English, specifically the compound words 'back' and 'pack', where 'back' meant 'the rear part of the body' and 'pack' meant 'a bundle to be carried'.

'backpack' changed from an earlier hyphenated form 'back-pack' in modern English usage and ultimately became the single word 'backpack'. The elements 'back' and 'pack' themselves come from Old English/Germanic and Middle English/Middle Dutch roots, respectively.

Initially, it meant 'a pack carried on the back', and over time it has retained that core meaning while also being used as a verb meaning 'to travel carrying a pack on the back'.