'bactericidin' originates from New Latin/modern scientific coinage, formed from the combining form 'bacteri-' (from Greek 'bakterion' meaning 'small staff, rod') and the element '-cidin' / '-cide' (ultimately from Latin 'caedere' meaning 'to kill').

'bactericidin' is a modern formation rather than a word with a long medieval history; it was coined in scientific/medical English by combining 'bacteri-' with suffixes used to denote killing agents (such as '-cide' or variant '-cidin'), and entered usage in technical contexts.

Initially coined to mean 'a substance that kills bacteria,' the term's basic meaning has remained stable and continues to denote antibacterial killing agents.