'zoophagous' originates from Greek, specifically the word 'ζῴοφαγος' (transliterated 'zōophagos'), where 'zōon' meant 'animal' and 'phagein' meant 'to eat'.

'zoophagous' entered English via Neo-Latin/Scientific coinage in the 19th century, formed directly from the Greek roots and used in zoological and biological descriptions.

Initially it meant 'feeding on animals' in a literal, biological sense; over time this core meaning has remained stable and is retained in scientific usage.