'insufferable' originates from Latin, specifically the word 'insufferabilis,' where 'in-' meant 'not' and 'sufferabilis' meant 'able to be endured.'

'insufferabilis' transformed into the Old French word 'insufferable,' and eventually became the modern English word 'insufferable.'

Initially, it meant 'unable to be endured,' and this meaning has largely remained the same in modern usage.