'man-eater' originates from English compound elements ultimately from Old English: 'man' (Old English 'mann') meaning 'person' and 'eat' (Old English 'etan') meaning 'to eat', with the agent suffix '-er' forming 'eater'.

'man-eater' developed in Middle English as a compound (e.g. 'man-eter') combining 'man' + agent form of 'eat' and eventually standardized in Modern English as 'man-eater'.

Initially it meant a being that literally ate humans; over time it retained that literal sense while also gaining a figurative sense of a person (often a woman) who 'devours' men emotionally or socially.