'antiviral' originates from Greek and Latin: the prefix 'anti-' originates from Greek 'anti' where 'anti-' meant 'against', and 'viral' derives from Late Latin 'virus' where 'virus' meant 'poison'.

'antiviral' changed from the combining of Greek prefix 'anti-' + English adjective 'viral' (itself from Late Latin 'virus'); the specific compound 'antiviral' arose in 20th-century medical English to name agents acting against viruses.

Initially it meant 'against virus' in a literal composition sense, but over time it evolved into the specific modern meaning of 'relating to or denoting drugs or agents that inhibit viruses'.