'non-citizen' originates from the prefix 'non-' meaning 'not' and the word 'citizen' from Middle English 'citizein', which meant 'inhabitant of a city'.

'citizein' transformed into the modern English word 'citizen', and with the addition of the prefix 'non-', it became 'non-citizen'.

Initially, 'citizen' meant 'inhabitant of a city', but over time it evolved to mean 'a legally recognized subject or national of a state'. 'Non-citizen' thus refers to someone who does not hold this status.