'unshaken' originates from the prefix 'un-' meaning 'not' and the word 'shaken', which comes from Old English 'sceacan', meaning 'to move quickly'.

'sceacan' transformed into the Middle English word 'shaken', and eventually became the modern English word 'shake'. The prefix 'un-' was added to form 'unshaken'.

Initially, 'shaken' meant 'to move quickly', but over time, 'unshaken' evolved to mean 'not disturbed or moved'.