IV 1 (??v??)n. An apparatus for providing intravenous injections.[From i(ntra)v(enous).]IV 2abbr.1. intravenous2. intravenouslyAmerican 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.IV (?a??vi) n., pl. IVs, IV’s. an apparatus for intravenous delivery of electrolyte solutions, medicines, and nutrients. [1950?55; i(ntra) v(enous)] IV 1. intravenous. 2. intravenous injection. 3. intravenously. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.