The free folk refer to all Westerosi south of the Wall as southron. The name is also employed outside of the Westerosi context. By the Isle of Cedars, Victarion Greyjoy thinks of the treacherous storms encountered by the Iron Fleet as “southron storms”.
If Your Grace wishes to lose all of my lord father's bannermen, there is no more certain a way than by giving northern halls to southron lords.
Another bloody southron fool.