'non-obvious' originates from the prefix 'non-' meaning 'not' and the word 'obvious', which comes from Latin 'obvius', meaning 'in the way' or 'easy to see'.

'obvius' transformed into the French word 'obvie', and eventually became the modern English word 'obvious'.

Initially, 'obvious' meant 'in the way' or 'easy to see', but over time it evolved into its current meaning of 'easily perceived or understood'.