'unmooring' originates from the prefix 'un-' meaning 'not' or 'opposite of', and the word 'moor', which comes from Old English 'mōrian', meaning 'to fasten a ship'.

'unmoor' changed from the Old English word 'mōrian' and eventually became the modern English word 'unmoor'.

Initially, it meant 'to release a ship from its moorings', and this meaning has largely remained the same in modern usage.