'insensible' originates from Latin, specifically the word 'insensibilis,' where 'in-' meant 'not' and 'sensibilis' meant 'capable of feeling.'

'insensibilis' transformed into the Old French word 'insensible,' and eventually became the modern English word 'insensible' through Middle English.

Initially, it meant 'not capable of feeling,' but over time it evolved into its current meaning of 'unaware or indifferent to.'