monkey wrenchmonkey wrenchn.1. A hand tool with adjustable jaws for turning nuts of varying sizes.2. Informal Something that disrupts: He threw a monkey wrench into our plans.[Origin unknown.]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.monkey wrench n (Tools) a wrench with adjustable jaws Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014mon?key wrench` n. 1. a wrench having an adjustable jaw for grasping nuts of different sizes. 2. something that interferes. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.Monkey wrenchOne of the few types of wrenches found on most early-twentieth-century farms. Its jaws were at right angles to the handle. One jaw was adjustable. The other, much heavier and at the end of the handle, was often used as a hammer. Charles Moncky apparently invented the wrench sometime before 1860.1001 Words and Phrases You Never Knew You Didn?t Know by W.R. Runyan Copyright © 2011 by W.R. Runyan