Reluctant to join Scotsman in part of his country (7)
I believe the answer is:
lothian
'part of his country' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'reluctant to join scotsman' is the wordplay.
'reluctant' becomes 'loth' (synonyms).
'to join' means one lot of letters go next to another.
'scotsman' becomes 'ian' (common Scottish name).
'loth'+'ian'='LOTHIAN'
'in' is the link.
(Other definitions for lothian that I've seen before include "Edinburgh area" , "Historic Scottish region" .)