n. A suburb undergoing rapid population growth.
2001
With its retail and restaurant components and luxury apartments neatly arranged on a 20-acre site, the village breaks the Southwest mold of suburban development. It recognizes that our suburbs are now fast-growing, big cities — 'boomburbs' is the new phrase coined for them.
2001 (earliest)
Boomburbs are defined as places with more than 100,000 residents that are not the largest city in their metropolitan areas and have maintained double-digit rates of population growth in recent decades. The United States currently contains 53 Boomburbs: four top 300,000 in population, eight surpass 200,000, and 41 exceed 100,000 people. This Census Note follows these important but seldom recognized places, which accounted for over half (51 percent) of 1990s' growth in cities with between 100,000 and 400,000 residents. Boomburbs now contain a quarter of all people who live in such places.
This word was coined by a couple of urban planners from the Fannie Mae Foundation in a report delivered on June 22, 2001 to the 69th Annual Conference of Mayors in Detroit. An excerpt from that report is reprinted as the earliest citation. Like the object it describes, the word boomburb itself appears to be undergoing rapid growth because I was able to find no less than six citations that used the word without referring to the Fannie Mae report.