an·ti·ven·in (?n?t?-v?n??n, ?n?t?-)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.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.antivenin (?ænt??v?n?n) or antivenenen (Pharmacology) an antitoxin that counteracts a specific venom, esp snake venom[C19: from anti- + ven(om) + -in]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014an?ti?ven?in (?æn ti?v?n ?n, ?æn ta?-) also an?ti?ven?om (-?v?n ?m) n. an antitoxin that counteracts venom, as from snakebite, obtained from the serum of a large animal that has had a series of controlled venom injections: used for treating victims of venomous bites. [1900?05] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.antivenin1. an antidote for venom, as snake venom, formed by gradually increased injection of the venom into the bloodstream.2. the serum containing this antidote.See also: Remedies-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.