Zealot from Iran put in trouble (7)
I believe the answer is:
puritan
'zealot' is the definition.
(thesaurus)
'iran put in trouble' is the wordplay.
'in trouble' indicates an anagram.
'iran'+'put'='iranput'
'iranput' with letters rearranged gives 'PURITAN'.
'from' acts as a link.
(Other definitions for puritan that I've seen before include "Killjoy" , "Strict person for whom pleasure is sinful" , "Over-strict moralist" , "One with very strict moral principles" , "narrow-minded" .)