'animal-eater' originates from Modern English, a compound of the noun 'animal' and the agent noun 'eater', where 'animal' meant 'a living being' and 'eater' meant 'one who eats'.

'animal' comes from Latin 'animalis' (from 'anima' meaning 'breath, soul'), which entered English via Old French/Medieval Latin; 'eater' descends from Old English 'etan' (to eat) with the agentive suffix '-er', and the two were combined in Modern English to form the compound 'animal-eater'.

Initially, the components referred separately to 'a living being' and 'one who eats'; over time the compound came to denote specifically 'one that eats animals' (either animal predators or people who eat meat).