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 Illinois (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

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The first known use of Illinois was in 1703

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Cite this Entry

“Illinois.” Dictionary, Merriam-Webster, Accessed 5 Mar. 2021.

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