'non-sexual' originates from the prefix 'non-' meaning 'not' and the word 'sexual' from Latin 'sexualis', where 'sexus' meant 'sex'.

'sexualis' transformed into the French word 'sexuel', and eventually became the modern English word 'sexual'.

Initially, it meant 'related to sex', but with the prefix 'non-', it evolved into its current meaning of 'not related to sex'.