Q&A With Jeffery Eugenides
Why is their house called "Middlesex?"
— Peggy N.
The house isn't really called "Middlesex." Not, at least, in the way "Wuthering Heights" was called "Wuthering Heights." "Middlesex" is simply the name of the street the Stephanides lived on. Cal refers to the house by its street address in the way people call The White House 1600 Pennsylvania Avenue.
— Jeffrey Eugenides