'bacteriophagous' originates from the combining form 'bacterio-' (from Greek 'bakterion', meaning 'small staff' or 'rod') and the Greek-derived suffix '-phagous' (from 'phagein', meaning 'to eat'), assembled in Neo-Latin to describe organisms that eat bacteria.

'bacteriophagous' was formed by combining the neo-Latin/Greek elements 'bacterio-' + '-phagous', modeled in scientific coinages of the late 19th and early 20th centuries (around the time terms like 'bacteriophage' were coined) and entered English use in scientific contexts.

Initially it referred specifically to organisms that consume bacteria; this core meaning has been retained in modern scientific usage to describe bacteria-eating organisms or behaviors.