'unimpressed' originates from the prefix 'un-' meaning 'not' and the word 'impressed', which comes from Latin 'imprimere', meaning 'to press into'.

'imprimere' transformed into the Old French word 'imprimer', and eventually became the modern English word 'impress'.

Initially, 'impress' meant 'to press into', but over time it evolved into its current meaning of 'to affect deeply or strongly'.