an·ti·ven·in 
(ăn′tē-vĕnĭn, ăn′tī-)
(ăn′tē-vĕnĭn, ăn′tī-)n.
1. An antitoxin active against the venom of a snake, spider, or other venomous animal or insect.
2. An animal serum containing antivenins. It is used in medicine to treat poisoning caused by animal or insect venom.
[ANTI- + VEN(OM) + -IN.]