• synonyms


[il-uh-noi-uh n]
  1. Geology. the third stage of the glaciation of North America during the Pleistocene.
  2. Illinoisan.
Show More
  1. Geology. of or relating to the Illinoian stage.
  2. Illinoisan.
Show More

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

  • Specific identification of the Illinoian pocket gophers is uncertain, primarily due to the fragmentary nature of the material.

    Evolution and Classification of the Pocket Gophers of the Subfamily Geomyinae

    Robert J. Russell

  • The ancient channel which it held along the Illinoian ice front has been traced through southeastern Iowa for many miles.

    The Elements of Geology

    William Harmon Norton