'anti-contagionism' is formed from the prefix 'anti-' (from Greek anti 'against'), the noun 'contagion' (from Latin 'contagio'/'contagion-', from 'contagĭō' meaning 'a touching or contact' derived from 'contingĕre' 'to touch/affect'), and the suffix '-ism' (from Greek/Latin via modern English denoting a doctrine or system).

'contagion' passed from Latin 'contagĭō' into Old French as 'contagion' and into Middle English as 'contagion'; the compound 'anti-contagionism' arose in English in the 19th century to name the movement opposing contagionist explanations of disease.

Initially it referred specifically to the 19th-century medical and public-health stance opposing person-to-person contagion; over time it has remained a historical term used to describe that doctrine or proponents of that view.