'unsinkable' originates from the prefix 'un-' meaning 'not' and the word 'sink,' which comes from Old English 'sincan,' meaning 'to become submerged.'

'sink' changed from the Old English word 'sincan' and eventually became the modern English word 'sink.'

Initially, 'sink' meant 'to become submerged,' and 'unsinkable' evolved to mean 'incapable of sinking.'