'non-convertibility' originates from the prefix 'non-' meaning 'not' and the word 'convertibility', which comes from the Latin 'convertibilis', meaning 'able to be turned around'.

'convertibilis' transformed into the English word 'convertible', and eventually became 'convertibility' with the addition of the suffix '-ity'. The prefix 'non-' was added to form 'non-convertibility'.

Initially, 'convertibility' meant 'the ability to be converted', and with the prefix 'non-', it evolved to mean 'the inability to be converted'.