Green section of a Risk board (4)
I believe the answer is:
asia
'green section of a risk board' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for asia that I've seen before include "A is A (anag)" , "A great deal of land" , "Great continent" , "The nations of the East, collectively" , "group of countries" .)