'whiten' originates from Old English, specifically the word 'hwitnian', where 'hwit' meant 'white' and the suffix '-nian' was used to form verbs (causative).

'whiten' changed from Old English 'hwitnian' and through Middle English forms (such as 'whiten') to become the modern English word 'whiten'.

Initially, it meant 'to make white' or 'cause to be white'; over time this basic meaning has been retained, though it has broadened to include 'to make pale' or 'to bleach'.