Definition of "monkey wrench" []

• A hand tool with adjustable jaws for turning nuts of varying sizes. (noun)
• Informal Something that disrupts: He threw a monkey wrench into our plans. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Plumm told Crosse about Dunross's takeover bid. "lan's thrown a monkey wrench into Pug.""
• "A major monkey wrench had been tossed into the main theory: Pavel Menansi had been murdered too, in a fashion similar to Valerie Simpson."