'unsheathe' originates from Old English elements: the prefix 'un-' and the base 'sheathe' (Old English 'scēath' / 'scēath'), where 'un-' meant 'reverse' or 'remove' and 'scēath' meant 'covering' or 'scabbard'.

'sheathe' appeared in Old English as 'scēath' and entered Middle English as 'schethe'/'shethe'; the verb formation with 'un-' (Middle English forms like 'unshethen'/'unsheathen') eventually became the modern English 'unsheathe'.

Initially, it meant 'to remove from a sheath' (literal action), but over time it also came to be used figuratively to mean 'to reveal or expose' something hidden.