From Longman Dictionary of Contemporary EnglishMiddle AmericaˌMiddle Aˈmerica noun [uncountable] 1 SGthe middle part of the United States, which is not on the east or west coasts2 CLASS IN SOCIETYAmericans who are neither very rich nor very poor and who have traditional ideas and beliefs
Examples from the Corpus
Middle America• Car buyers in Middle America are looking for value and comfort.• Asian immigrants have been moving into middle America in greater numbers. 