'impermissible' originates from the Latin word 'permissibilis,' where 'per-' meant 'through' and 'mittere' meant 'to send.'

'permissibilis' transformed into the Old French word 'permissible,' and eventually became the modern English word 'impermissible' by adding the prefix 'im-' to indicate negation.

Initially, it meant 'capable of being allowed,' but over time it evolved into its current meaning of 'not allowed or permitted.'