'bacteriocidal' originates from New Latin/Modern Latin, specifically from the combining form 'bacterio-' (from Latin 'bacterium', from Greek 'bakterion') plus the suffix '-cidal' (from Latin 'cidus'/'-cida', ultimately from 'caedere'), where 'bakterion' meant 'small staff' and 'caedere' meant 'to kill'.

'bacteriocidal' developed after the scientific coinage of 'bacterium' (from Greek 'bakterion' → Latin 'bacterium') and the productive English suffix '-cidal' (from Latin roots meaning 'to kill'), forming a modern English adjective meaning 'killing bacteria'.

Initially the roots referred literally to a 'small staff' (bakterion) and 'to kill' (caedere) as parts of their original languages, but combined in modern scientific English the word came to mean 'capable of killing bacteria'.