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Cahokia Mounds

noun
  1. a group of very large prehistoric Indian earthworks in southwestern Illinois, consisting of mounds with flat tops that supported temples and other structures of mud and thatch.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for cahokia mounds

Cahokia Mounds

pl n
  1. the largest group of prehistoric Indian earthworks in the US, located northeast of East St Louis
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012