'folivore' originates from Neo-Latin, specifically from 'folivorus', where 'folium' meant 'leaf' and '-vorus' (from Latin 'vorare') meant 'to devour'.

'folivore' was formed in modern scientific English from Neo-Latin 'folivorus' (itself composed from Latin elements 'folium' + 'vorare'), and entered English as a coined ecological/zoological term meaning 'leaf-eating animal'.

Initially, the components meant 'leaf' and 'to devour'; the coined term retained that literal sense and evolved into the technical term for animals that eat mainly leaves.