Region in the Far East (4)
I believe the answer is:
area
'region' is the definition.
(I know that area can be written as area)
'in the far east' is the wordplay.
'in' indicates a hidden word.
'AREA' is hidden in the letters of 'far east'.
(Other definitions for area that I've seen before include "land" , "Length multiplied by breadth" , "Expanse of a surface" , "Geographical region" , "environs" .)