'contagion' originates from Latin, specifically the word 'contagionem,' where 'con-' meant 'together' and 'tangere' meant 'to touch.'

'contagionem' transformed into the Old French word 'contagion,' and eventually became the modern English word 'contagion' through Middle English.

Initially, it meant 'contact or touch,' but over time it evolved into its current meaning of 'transmission of disease or influence.'