Modern Persian rain troubled man (7)
I believe the answer is:
iranian
'modern persian' is the definition.
'rain troubled man' is the wordplay.
'troubled' is an anagram indicator.
'man' becomes 'ian'.
'rain' anagrammed gives 'iran'.
'iran'+'ian'='IRANIAN'
(Other definitions for iranian that I've seen before include "One from Isfahan" , "foreigner" , "Foreign national" , "Asian citizen" , "Khamenei or Rouhani, say" .)