Informal One who lacks initiative, imagination, or enthusiasm.(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.
Use "stick-in-the-mud" in a sentence
"Standout scene: Andrew's mother (Mary Steenburgen) and frisky, 90-year-old "Gammy Annie" (Betty White) drag stick-in-the-mud Margaret to a bar for a makeshift bachelorette party."
"The truly sad thing is the reaction of all you stick-in-the-mud drones who think Governor Sanford has, somehow, done something wrong."
"She's a polarizing, non-transformational, stick-in-the-mud figure who has a history of making brash, knee-jerk decisions."