Game is a Southern game (4)
I believe the answer is:
stag
'game' is the definition.
(stags are game in the hunting sense)
'southern game' is the wordplay.
'southern' becomes 's' (abbreviation).
'game' becomes 'tag' (children's playground game).
's'+'tag'='STAG'
'is a' acts as a link.
(Other definitions for stag that I've seen before include "Investor" , "Deer; with only men" , "Antlered animal" , "Male beast" , "Adult male deer, often with antlers" .)