The word 'whitening' is built upon the ancient Germanic root for the color white, which can be traced back to the Proto-Indo-European root ḱweyt-, meaning "to shine; white." The Old English adjective hwīt was combined with the productive verb-forming suffix -en, creating the verb 'whiten,' meaning "to make or become white." Finally, the addition of the gerund or action-noun suffix -ing transforms the process into a concrete noun. Thus, the term's logic flows directly from the core concept of the color, through the action of causing that state, to the name of the process or product itself.

Structure: white (color) + en (verb suffix) + ing (noun suffix) - white: From Old English hwīt, meaning the color white. Its functional role is the core adjective/root. - en: A verb-forming suffix from Old English -nian, used to form verbs meaning "to become or make something have the quality of" the root. - ing: A suffix from Old English -ung, -ing, used to form nouns of action or result from verbs.