When somebody lives in a small
village, or small town and wants to describe where
they live. A town-town is a major town, that most people would know, like
Hastings instead or Battle or Crowhurst, which most people would have no idea where they were.
Harry: Hannah,
whereabouts do you live?
Hannah: Well, my nearest town-town is
Hastings, but I live in Crowhurst, near Catsfield and Battle.
Harry:
Oh right, I know Hastings.