Accost or detain a person in conversation. For example, The reporter tried to buttonhole the senator, but she got away. This term is a metaphor for literally grasping someone by a buttonhole on his or her clothing. [Mid-1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.