Il·​li·​nois | \ ˌi-lə-ˈnȯi How to pronounce Illinois (audio) also -ˈnȯiz How to pronounce Illinois (audio) \
plural Illinois

Definition of Illinois

 (Entry 1 of 2)

1 plural : a confederacy of American Indian peoples of Illinois, Iowa, and Wisconsin
2 : a member of any of the Illinois peoples
3 : the Algonquian language of the Illinois


geographical name
Il·​li·​nois | \ ˌi-lə-ˈnȯi also -ˈnȯiz How to pronounce Illinois (audio) \

Definition of Illinois (Entry 2 of 2)

1 river 273 miles (439 kilometers) long in Illinois flowing southwest into the Mississippi River
2 state in the central part of the U.S. having the Mississippi River as its western boundary and bordering on Lake Michigan in the northeast; capital Springfield area 56,400 square miles (146,640 square kilometers), population 12,830,632

Other Words from Illinois

Geographical name

Illinoisan \ ˌi-​lə-​ˈnȯi-​ən also -​ˈnȯi-​zᵊn How to pronounce Illinoisan (audio) \ adjective or noun

First Known Use of Illinois


1703, in the meaning defined at sense 1

History and Etymology for Illinois


French, earlier Eriniouai, singular, probably from a word in an Algonquian language derived from Proto-Algonquian *elen- ordinary + *-we· make a sound

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Time Traveler for Illinois

Time Traveler

The first known use of Illinois was in 1703

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Statistics for Illinois

Cite this Entry

“Illinois.” The Dictionary, Merriam-Webster Inc., Accessed 28 January 2020.

More from Merriam-Webster on Illinois

Rhyming Dictionary: Words that rhyme with Illinois

Britannica English: Translation of Illinois for Arabic Speakers

Comments on Illinois

What made you want to look up Illinois? Please tell us where you read or heard it (including the quote, if possible).


showing steady, earnest care and effort

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