Illinoian

[il-uh-noi-uh n]
adjective
  1. Geology. of or relating to the Illinoian stage.
  2. Illinoisan.

Origin of Illinoian

An Americanism dating back to 1825–35; Illinoi(s) + -an
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for illinoian

Historical Examples of illinoian