Canadian Shield 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.
an area of about 2,000,000 sq mi (5,179,980 sq km) of Precambrian strata, consisting largely of granite, gneiss, marble, and other igneous and metamorphic rocks that occupy most of eastern and central Canada & part of NE U.S.
Canadian Shield definition by American Heritage Dictionary
See Laurentian Plateau.