'antivenin' originates from the prefix 'anti-' (from Greek, meaning 'against') combined with 'venin' from French 'venin' (from Latin 'venenum', meaning 'poison' or 'venom').

'antivenin' is a modern English formation influenced by French 'antivenin' and by the scientific use of 'anti-' + 'venin/venom' in the late 19th to early 20th century as therapies against animal venoms were developed.

Initially it specifically referred to animal-derived sera used to counteract venom; that core meaning has remained largely the same, though usage has broadened to include any antivenom preparations.