'unclad' originates from the prefix 'un-' meaning 'not' and the word 'clad,' which comes from Old English 'clæd,' meaning 'clothed.'

'clæd' transformed into the Middle English word 'clad,' and eventually became the modern English word 'clad.' The prefix 'un-' was added to form 'unclad.'

Initially, it meant 'not clothed,' and this meaning has largely remained the same in modern usage.