'antibacterial' originates from the prefix 'anti-' (Greek) meaning 'against' plus 'bacterial' from Latin 'bacterium' (from Greek 'bakterion' meaning 'little staff').

'antibacterial' developed in modern English from scientific compound formations: Greek 'anti-' + Latin/Neo-Latin 'bacterium' (from Greek 'bakterion'), producing the adjective 'antibacterial' and later the adverb 'antibacterially'.

Initially formed to mean 'against bacteria' in scientific/medical contexts; it has retained that core meaning and is used to describe substances or actions that inhibit or kill bacteria.