shotgun wedding definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a wedding into which one or both partners are forced, as because of previous sexual intimacy or, esp., pregnancy
shotgun wedding - Phrases/Idioms
An agreement or compromise made through necessity, as in Since neither side won a majority, the coalition government was obviously a shotgun wedding. This expression alludes to a marriage precipitated by a woman's pregnancy, causing her father to point a literal or figurative gun at the responsible man's head. Its figurative use dates from the mid-1900s.