'antisepticize' originates from Modern English, formed by combining 'antiseptic' and the verb-forming suffix '-ize', where 'antiseptic' meant 'preventing sepsis' and '-ize' meant 'to make or to render'.

'antiseptic' entered English via French 'antiseptique' (modern French) from Greek 'antiseptikos' (anti- 'against' + septikos 'causing putrefaction'), and the verb was created by adding '-ize' in English in the 19th century to form 'antisepticize' and its inflected forms such as 'antisepticized'.

Initially it referred specifically to preventing or counteracting sepsis/putrefaction; over time the meaning broadened to the general modern sense of 'to make sterile or disinfect'.