The BosWash megalopolis is the name for a group of metropolitan areas in the northeastern United States, extending from Boston to Washington and linked by economics, transport, and communications. The high-speed Amtrak train, the Acela, runs the length of the BosWash area.

BosWash contains a reported population of 44 million, or 16% of the population of the United States, and four of the world's fifty largest metropolitan areas — Boston, New York, Philadelphia, and Washington.

The geographic trend was first identified in the 1961 book Megalopolis: The Urbanized Northeastern Seaboard of the United States by French geographer Jean Gottman.
What makes you think of fast-paced life, cultural diversity, great schools, lots of traffic, four seasons, city-life, suburbia, and beaches galore all within close proximity of each other?

by Blaxican DC December 3, 2009
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The general term for any group of Eastern Europeans who will wash your car in a Tesco's car park for a fiver.
"Wow, my car's dirty. I can't be arsed to clean it myself, I'll go and get a boswash"
by Michael A A February 7, 2008
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The crowded region of the Eastern seabord of the U.S steretching from Boston, MA to the Washington DC Metro area. It has about 30 million people or so and is known for its traffic, high cost of living, enormous diversity, bad weather and downright bad attitude and rudeness by most of its people.
I would NEVER live in the Boswash region: the people suck and so does the traffic and weather.
by December 24, 2007
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