'anticancerous' originates from Modern English, specifically formed from the prefix 'anti-' (from Greek 'anti' meaning 'against'), the noun 'cancer' (from Latin 'cancer' via Old French), and the adjectival suffix '-ous'.

'cancer' originates from Latin 'cancer', which in turn reflects Greek 'karkinos' meaning 'crab'. The compound formation 'anti-' + 'cancer' + '-ous' is a Modern English/coined medical formation (20th century) that produced 'anticancerous'.

Initially it meant 'against cancer' in a literal/formative sense; over time it has been used specifically to describe agents or properties that prevent or inhibit cancer, a meaning that has been retained in modern usage.