'antiloimic' originates from Modern English coinage based on Greek elements: 'anti-' (against) + Greek 'loimos' meaning 'plague'.

'antiloimic' was formed in English from Neo-Latin/Modern-Latin formations such as 'antiloimicus' (built from Greek roots) and appears in medical and historical writing to mean 'against plague'.

Initially it meant 'opposed to plague' (literally against 'loimos'), and its usage has remained close to that original sense, referring to measures or agents that prevent or counter contagious epidemics.