'pollutant' originates from the Latin word 'polluere,' where 'pol-' meant 'to soil' and '-uere' meant 'to make dirty.'

'polluere' transformed into the Old French word 'polluer,' and eventually became the modern English word 'pollute,' from which 'pollutant' is derived.

Initially, it meant 'to soil or defile,' but over time it evolved into its current meaning of 'a substance that pollutes.'