'bacteriophagic' originates from Greek roots via Neo-Latin/modern scientific English, specifically the element 'bacterio-' from Greek 'bakterion', where 'bakterion' meant 'small staff' or 'rod', and '-phagic' from Greek 'phagein', where 'phagein' meant 'to eat'.

'bacteriophagic' developed from the noun 'bacteriophage' (coined in the early 20th century to name viruses that 'eat' bacteria) with the addition of the adjectival suffix '-ic' to form an adjective used in scientific contexts.

Initially the roots described the literal idea of 'eating bacteria'; over time the combined form has been used adjectivally to describe agents, organisms, or processes that destroy or consume bacteria.