7 Cities
A passing fad of that is a misnomer for the Hampton Roads region of southeastern Virginia, USA.

It is considered a misnomer because:
1) It does not identify the area in any concrete terms.

2) The name excludes a large portion of the metropolitan area in southeastern Virginia (Williamsburg, Poquoson, York County, Northeast North Carolina, Gloucester, Franklin, Smithfield, Isle of Wight)

3) It doesn't make any sense to say I live in the 7 cities. Really, you live in 7 different places.
You: Yo dude, lets hang in the 7 cities tonight!

Me: Man, that word is so 2000. I'm going to Norfolk.