Someone who habitually takes on burdensome or unpleasant tasks or unreasonable amounts of work. For example, Rose agreed to organize the church fair for the third year in a row—she's a glutton for punishment. This expression originated as a glutton for work in the late 1800s, punishment being substituted about a century later.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.