'actinomycosis' originates from Greek, specifically the word 'aktis' meaning 'ray' and 'mykes' meaning 'fungus', where 'actino-' referred to the radiating structure of the bacteria.

'actinomycosis' changed from the Greek word 'aktinomyces' and eventually became the modern English word 'actinomycosis'.

Initially, it meant 'ray fungus', but over time it evolved into its current meaning of 'a chronic bacterial infection'.