'unzip' originates from the prefix 'un-' meaning 'reverse action' and 'zip' from the word 'zipper', which is a fastening device.

'unzip' was formed by adding the prefix 'un-' to 'zip', creating a word that means to reverse the action of zipping.

Initially, it meant 'to undo a zipper', and this meaning has largely remained the same in modern usage.