'scrub' originates from Middle Dutch, specifically the word 'schrobben', where 'schrob-' meant 'to rub hard'.

'schrobben' transformed into the English word 'scrub' and eventually became the modern English word 'scrubbing' through the addition of the present participle suffix '-ing'.

Initially, it meant 'to rub hard', but over time it evolved into its current meaning of 'cleaning by rubbing hard'.