'indisposed' originates from Latin, specifically the word 'indispositus,' where 'in-' meant 'not' and 'dispositus' meant 'arranged or disposed.'

'indispositus' transformed into the French word 'indisposé,' and eventually became the modern English word 'indisposed' through Middle English.

Initially, it meant 'not arranged or disposed,' but over time it evolved into its current meanings of 'slightly ill' and 'unwilling.'