Doctor, not green, wandering in the country (10)
I believe the answer is:
montenegro
'country' is the definition.
(I've seen this before)
'doctor not green wandering in' is the wordplay.
'doctor' becomes 'mo' (medical officer).
'wandering' indicates an anagram.
'in' is an insertion indicator.
'not'+'green'='notgreen'
'notgreen' is an anagram of 'ontenegr'.
'mo' placed around 'ontenegr' is 'MONTENEGRO'.
'the' is the link.
(Other definitions for montenegro that I've seen before include "European country (bordering on 6)" , "Balkan republic" , "Balkan state" .)