'inextinguishable' originates from Latin, specifically the word 'inextinguibilis,' where 'in-' meant 'not' and 'extinguere' meant 'to quench or put out.'

'inextinguibilis' transformed into the Old French word 'inextinguible,' and eventually became the modern English word 'inextinguishable.'

Initially, it meant 'impossible to quench or put out,' and this meaning has largely remained the same in modern usage.