micropolitan

adj

1. (US, not-comparable)Of or pertaining to a city or twin cities having at least 10,000 but fewer than 50,000 inhabitants; of a city: less populated than a metropolitan area but more than a rural one.

noun

1. (US)A city or twin cities having at least 10,000 but fewer than 50,000 inhabitants; a city which is less populated than a metropolitan area but more than a rural one.

   “For marketing experts who help companies decide where to expand, the "micropolitans" represent potentially lucrative – and untapped – markets. More than 28 million people, or one in 10 Americans, live in such areas.”