Country is dull? Not initially (4)
I believe the answer is:
land
'country' is the definition.
('land' can be a synonym of 'country')
'dull? not initially' is the wordplay.
'dull?' becomes 'bland' ('bland' can be similar in meaning to 'dull').
'not initially' means to remove the first letter.
'bland' with its first letter removed is 'LAND'.
'is' is the link.
(Other definitions for land that I've seen before include "Terrain" , "German region" , "Part of Germany" , "part of surface" , "Alight; country" .)