'animal-eater' originates from Modern English, specifically a compound of the noun 'animal' and the agent noun 'eater'. 'animal' ultimately comes from Latin 'animalis', where 'anima' meant 'breath' or 'soul'; 'eat' comes from Old English 'etan' meaning 'to eat', with the agentive suffix '-er' forming 'eater'.

'animal' entered English via Old French 'animal' from Latin 'animalis'; 'eat' developed from Old English 'etan' (Modern English 'eat'), and the compound 'animal-eater' arose in Modern English by compounding these elements to denote an organism that eats animals.

Initially used straightforwardly to denote animals that eat other animals; over time the literal meaning remained but the term also acquired occasional figurative uses to describe aggressive or predatory people.