RhymeZone: illinoian definitions

Definitions of Illinoian:

adjective: (geology) Of or relating to the Illinoian stage.
noun: (geology) A stage of the last Ice Age in North America, lasting from around 190,000 to 130,000 years ago.
adjective: Alternative form of Illinoisan [Of or relating to Illinois, one of the United States.]
noun: Alternative form of Illinoisan [A native or resident of the state of Illinois in the United States of America.]

(Definitions from Wiktionary)