'malaria-fighting' originates from Modern English as a compound of 'malaria' and the present participle 'fighting' (from 'fight'), where 'malaria' names the disease and 'fighting' means 'combating or opposing'.

'malaria' comes from Italian 'mala aria' meaning 'bad air' (from Medieval belief about the cause of the disease) and entered English as 'malaria' in the 18th century; 'fight' comes from Old English 'feohtan' meaning 'to fight', which developed into Modern English 'fight' and the participle 'fighting'. The compound 'malaria-fighting' is a recent productive formation in English combining the disease name with a gerund/participle to form an adjective.

Initially, 'malaria' literally reflected the idea of 'bad air', but over time it shifted to mean the infectious disease caused by parasites; 'fight' originally meant physical combat and evolved to include figurative senses such as 'to work to eliminate'—together yielding the modern sense 'combating malaria'.