Illinois
1 Americannoun
-
a member of a confederacy of North American Indians of Algonquian stock, formerly occupying Illinois and adjoining regions westward.
-
the Algonquian language of the Illinois and Miami Indians.
noun
-
a state in the central United States: a part of the Midwest. 56,400 sq. mi. (146,075 sq. km). Springfield. IL (for use with zip code), Ill.
-
a river flowing southwest from northeastern Illinois to the Mississippi River: connected by a canal with Lake Michigan. 273 miles (440 km) long.
noun
-
Abbreviation: Ill.. IL. a state of the N central US, in the Midwest: consists of level prairie crossed by the Illinois and Kaskaskia Rivers; mainly agricultural. Capital: Springfield. Pop: 12 653 544 (2003 est). Area: 144 858 sq km (55 930 sq miles)
-
a river in Illinois, flowing SW to the Mississippi. Length: 439 km (273 miles)
Pronunciation
The pronunciation of Illinois with a final , which occurs chiefly among less educated speakers, is least common in Illinois itself, increasing in frequency as distance from the state increases.
Discover More
Known as the “Land of Lincoln” because Abraham Lincoln began his political career there.
Other Word Forms
Etymology
Origin of Illinois
1715–25, < French, earlier Eriniouai, Ilinoués, etc., from an unidentified Algonquian language, apparently literally, “one who sounds normal” (i.e., “a person who speaks an Algonquian language”), equivalent to the (unattested) Proto-Algonquian elements elen- “ordinary” + -we “make sound”
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
What was in the water in Park Forest, Illinois?
From Salon • Jun. 9, 2026
Jonathan Pearce: Born in Illinois, this attacking midfielder actually played twice for the US in 2025 before switching allegiance to the country of his parents last November.
From BBC • Jun. 9, 2026
She started support groups more than 20 years ago throughout her home state of Illinois to help other grandfamilies.
From MarketWatch • Jun. 8, 2026
Illinois Secretary of State Alexi Giannoulias, whose office regulates motor vehicles, helped to draft legislation that requires anyone riding one of the bikes on the street to have a driver’s license, title, registration and insurance.
From The Wall Street Journal • Jun. 7, 2026
“Give me the Dewey decimal number for ‘freedom of speech,’” said Tabatha Otto, a librarian from Lincolnshire, Illinois.
From "Mr. Lemoncello's Library Olympics" by Chris Grabenstein
![]()
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.