'bacteriophagy' originates from Modern scientific formation using Greek elements, specifically from Greek 'bakterion' where 'bakteri-' meant 'little rod' (hence 'bacteria') and Greek 'phagein' where '-phagy' meant 'to eat'.

'bacteriophagy' was formed in modern scientific English by combining the New Latin/English term 'bacteriophage' (coined in the early 20th century) with the suffix '-y' (or the noun-forming Greek '-phagy'), resulting in the noun 'bacteriophagy'.

Initially formed to denote the act or phenomenon of 'phages eating/infecting bacteria', its usage has broadened to include applied practices such as phage therapy and ecological descriptions of phage predation.