Chaco 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.
extensive lowland plain in central South America, stretching across parts of Argentina, Paraguay, and Bolivia: c. 300,000 sq mi (776,997 sq km)
Chaco definition by American Heritage Dictionary
See Gran Chaco.