'inconvertibility' originates from the Latin word 'inconvertibilis,' where 'in-' meant 'not' and 'convertibilis' meant 'able to be converted.'

'inconvertibilis' transformed into the French word 'inconvertibilité,' and eventually became the modern English word 'inconvertibility.'

Initially, it meant 'not able to be converted,' and this meaning has largely remained the same in modern usage.