Illinois
1 Americannoun
plural
Illinois-
a member of a confederacy of North American Indians of Algonquian stock, formerly occupying Illinois and adjoining regions westward.
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the Algonquian language of the Illinois and Miami Indians.
noun
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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.
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a river flowing southwest from northeastern Illinois to the Mississippi River: connected by a canal with Lake Michigan. 273 miles (440 km) long.
noun
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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)
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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.
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.
The traditionally bipartisan organization, which seeks to work towards a majority pro-Israel US Congress, saw mixed success in Illinois, with two of its four preferred candidates winning their primaries.
From Barron's • Apr. 9, 2026
I briefly joined a book club of some work colleagues when I was teaching in rural Illinois, and it was fun, but most of our time was spent gossiping about, well, work.
From Los Angeles Times • Apr. 9, 2026
Illinois Governor JB Pritzker has also pushed the government to release the funding, saying the fish pose an “existential threat” to the Great Lakes.
From The Wall Street Journal • Apr. 8, 2026
The fossil was discovered at a site at Mazon Creek in Illinois, US, with the first analysis of it published in 2000.
From BBC • Apr. 8, 2026
They camped for the night in a grove of tall white sycamores, right on the bank of the Illinois River.
From "Summer of the Monkeys" by Wilson Rawls
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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.