MI vs Midwest

MI and Midwest both are nouns.

Word	Noun	Adjective	Verb	Adverb
MI	Yes	No	No	No
Midwest	Yes	No	No	No

MI (noun)	Midwest (noun)
the government agency in the United Kingdom that is responsible for internal security and counterintelligence on British territory	the north central region of the United States (sometimes called the heartland or the breadbasket of America)
the government agency in the United Kingdom that is responsible for internal security and counterintelligence overseas
a midwestern state in north central United States in the Great Lakes region, with capital Lansing
destruction of heart tissue resulting from obstruction of the blood supply to the heart muscle