Munster or Leinster (8)
I believe the answer is:
province
'munster or leinster' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for province that I've seen before include "Administrative district of country" , "Munster or Leinster, say" , "Sphere of action; administrative area" , "Area of activity" , "Major division of Ireland,or range of responsibility" .)