'chlorination' originates from the verb 'chlorinate' in Modern English, built from the combining form 'chloro-' (from Greek 'chloros' meaning 'green') and the verb-forming suffix '-ate', plus the noun-forming suffix '-tion'.

'chlorination' developed from Latin/Greek roots through scientific Latin and Modern English: Greek 'chloros' → Neo-Latin/Modern chemical term 'chlorine' and verb 'chlorinate' → English noun 'chlorination' formed by adding '-tion'.

Initially the root 'chloro-' referred to the color 'green', but with the discovery of the chemical element chlorine it came to indicate substances or reactions involving chlorine; 'chlorination' now specifically means treating or reacting with chlorine.