Midwest

wiktionary

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mid- +‎  West

etymonline

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Midwest (n.)

1926 in the U.S. geographical sense, from earlier Midwestern (1889) in reference to a group of states originally listed as West Virginia, Kentucky, Tennessee, Missouri, Kansas, and Arkansas; it now generally refers to states somewhat north and west of these (according to the U.S. Census Bureau, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin). Related: Midwesterner.