Whiten comes from white + the verb-forming suffix -en, from Old English hwīt ('white'), from Proto-Germanic *hwītaz, from Proto-Indo-European *kweid- ('to shine, be bright'). In current use it is a verb meaning "to make or become white or paler". That sense is explained by the older material without requiring a speculative semantic step: the inherited or borrowed base supplies the field of meaning, while the English formation fixes its modern role. The surface form is compositional: its joined elements remain visible in the modern word. The historical chain includes Old English hwīt and Proto-Indo-European *kweid-. Related English forms include white and whiteness. Derived forms include whitener and whitening. The word's history is thus visible in its construction: the components remain interpretable even after the whole expression has settled into a conventional English meaning.