Southernism

It is one of the national peccadilloes that anyone who lives north of St. Albans has some kind of prejudice against Londoners — perhaps "prejudice" is the wrong word — or rather not against Londoners but against southernism.

I loved his languid, Southern speech and little southernisms, like "you can't put a sequin on a rat's ass."

Many are known southernisms in the sense that they are also cited in sources such as Dictionary of American Regional English (henceforth, DARE) or Carver (1987).