I managed to unite Scot and Persian (7)
I believe the answer is:
iranian
'persian' is the definition.
(I know that persian can be written as Iranian)
'i managed to unite scot and' is the wordplay.
'managed' becomes 'ran' (both can mean organised or was in charge of).
'to unite scot' becomes 'ia' (I can't explain this - if you can you should believe this answer much more).
'and' becomes 'n' (common abbreviation for 'and').
'i'+'ran'+'ia'+'n'='IRANIAN'
Can you help me to learn more?
(Other definitions for iranian that I've seen before include "from the Middle East" , "Native of modern Persia" , "Foreign national" , "Khamenei or Rouhani, say" , "Nationality of citizen of Tehran" .)